Chin. Phys. B

High-order doubly localized waves in (2+1)-dimensional Maccari system

Xue-Wei Yan(严学威), Jin-Jin Mao(茆晋晋), and Min-Jie Dong(董敏杰)

Chin. Phys. B, 2026, 35 (7): 070201. DOI: 10.1088/1674-1056/ae0682

Abstract ( 19 )

PDF (2057KB) ( 7 )

In this work, we explore the doubly localized wave solutions for the (2+1)-dimensional Maccari system using Hirota's bilinear method and Kadomtsev-Petviashvili (KP) hierarchy reduction method. These solutions illustrate the temporal evolution of a line rogue wave and a lump in the background of a breather or homoclinic orbit. The line rogue wave in these solutions is characterized by two endpoints, and is thus referred to as a line-segment rogue wave. The lump is also a doubly localized wave known as a rogue lump, which is also localized in both time and two spatial dimensions. These waves emerge from the breather waves or homoclinic orbits and remain unchanged for a short period of time, eventually merging into other breather waves or homoclinic orbits. Notably, these rogue lumps appear and vanish alongside the homoclinic orbits and play a significant role in understanding extreme events in physical scenarios.

Reconstruction of detector error model for quantum error correction

Cheng Ye(叶澄) and Pan Zhang(张潘)

Chin. Phys. B, 2026, 35 (7): 070301. DOI: 10.1088/1674-1056/ae663a

Abstract ( 21 )

PDF (701KB) ( 3 )

Fault-tolerant quantum computing fundamentally relies on the accurate characterization of circuit-level noise to optimize decoding algorithms. However, extracting complex multi-body error correlations remains challenging. Contemporary greedy inference algorithms can suffer from statistical distortion, discarding true physical mechanisms while introducing many unphysical false positives. Here, we introduce the correlation-analysis-based hypergraph reconstruction (CAHR) algorithm, a globally consistent framework to invert experimental syndrome statistics directly into discrete physical hypergraphs. By coupling exact algebraic correlation equations with a top-down concurrent-pruning strategy, CAHR recovers the fault topology without false positives for both d = 5 rotated surface codes and dense 8-body 2D color codes in our benchmark settings. Furthermore, we show that exact continuous parameter extraction in dense codes is limited by a variance cascade, where absolute statistical variance accumulates linearly from high- to low-degree mechanisms. This motivates a two-stage inference paradigm: utilizing CAHR to extract the fault topology, followed by continuous probability optimization. This provides a practical approach for characterizing and decoding highly correlated noise in realistic quantum hardware.

Resource-aware distributed quantum circuits partitioning strategy and transmission cost optimization

Pengcheng Zhu(朱鹏程), Zongyuan Dai(戴宗原), Lihua Wei(卫丽华), Jin Qian(钱进), and Shi-Guang Feng(冯世光)

Chin. Phys. B, 2026, 35 (7): 070302. DOI: 10.1088/1674-1056/ae13ec

Abstract ( 14 )

PDF (2065KB) ( 2 )

To overcome the physical limitations of current quantum hardware in terms of available qubits and connectivity, distributed quantum computing (DQC) has emerged as a promising and scalable paradigm. However, in distributed settings, cross-node qubit interactions incur high communication overhead due to the use of costly quantum communication protocols. Efficient circuit partitioning and transmission cost optimization have thus become key challenges. This work addresses the often-overlooked issues of hardware heterogeneity and redundant transmission by proposing a resource-aware partitioning and transmission cost optimization method for distributed quantum circuits. First, we develop a partitioning framework constrained by qubit resources, which accommodates node capacity differences to enable flexible qubit allocation. Second, we model gate dependencies using a directed acyclic graph (DAG) representation and introduce formal criteria to detect ``initial-state" and ``final-state" redundancies. A measurement-reset strategy is then employed to replace part of the quantum communication, reducing inter-node data transmission. Experimental results on a variety of benchmark circuits and heterogeneous architectures demonstrate that our method significantly reduces transmission cost and improves overall resource utilization. These findings offer both theoretical insight and practical guidance for efficient distributed quantum computing.

Coherently manipulating triplet-exciton qubit by circularly polarized laser

Longlong Zhang(张龙龙), Hongwei Li(李宏伟), Zhenyu Xu(徐振宇), Mengze Tao(陶孟泽), Rui Chen(陈睿), and Yingqi Ma(马英起)

Chin. Phys. B, 2026, 35 (7): 070303. DOI: 10.1088/1674-1056/ae1450

Abstract ( 20 )

PDF (3221KB) ( 1 )

We theoretically propose a scheme for the coherent manipulation of a single qubit, which is constructed using the self-trapped triplet exciton (STTE) in FM/polymer/FM sandwich. The STTE serves as a quantum dot, comprising two degenerate triplet states with opposite magnetizations, thereby forming the qubit's subspace. We demonstrate that the spin state of this qubit can be coherently manipulated by applying an external circularly polarized laser (CPL) to form the Floquet state. The manipulation exhibits significant helicity dependence: when the CPL's angular momentum is antiparallel to the STTE's spin orientation, the STTE undergoes Rabi oscillations between the $|\uparrow\uparrow\rangle$ and $|\downarrow\downarrow\rangle$ state, corresponding to a $\pi$-rotation around the $x$-axis on the Bloch sphere. Conversely, when the CPL's angular momentum is parallel to the STTE's spin orientation, the STTE remains unresponsive to the CPL. Two-axis coherent control of the STTE qubit can be potentially realized by additionally applying a static magnetic field $B_{z}$. Our work provides a theoretical perspective for realizing the coherent manipulation of a qubit in organic devices.

An experimental proposal certification for any three-qubit generalized Greenberger-Horne-Zeilinger states based on fine-grained steering inequality

Zhi-Hao Bian(边志浩), Jia-Qi Sun(孙佳琪), and Yi Shen(沈毅)

Chin. Phys. B, 2026, 35 (7): 070304. DOI: 10.1088/1674-1056/ae0bfd

Abstract ( 20 )

PDF (929KB) ( 3 )

Multi-party quantum steering is an important concept in quantum information theory and quantum mechanics, typically related to quantum entanglement and quantum nonlocality. It enables precise manipulation of large quantum systems, which is essential for large-scale quantum computing, simulations, and quantum communication. Recently, a quantum steering certification for any three-qubit generalized Greenberger–Horne–Zeilinger (GGHZ) state based on the fine-grained steering inequality was proved [Quantum Studies: Mathematics and Foundations 9 175 (2022)]. Here we provide an experimental proposal to prepare the GGHZ state in a photon system. The measurement observables in each party can be realized by different polarization optical elements. By choosing the angles of the waveplates, our experimental proposal can observe the maximum quantum violation for any three-qubit GGHZ state. Our proposal can be easily extended to high-dimensional qubits and multi-photon GHZ states, which provides a method to study the complex multi-party quantum protocols.

Enhanced multiscale quantum approximate optimization algorithm in multibody combinatorial optimization problems

Lei-Lei Chen(陈蕾蕾), Ping Zou(邹平), and Ya-Fei Yu(於亚飞)

Chin. Phys. B, 2026, 35 (7): 070305. DOI: 10.1088/1674-1056/ae29f7

Abstract ( 8 )

PDF (902KB) ( 0 )

At present, the quantum approximate optimization algorithm (QAOA) faces scalability challenges in high-dimensional combinatorial optimization problems due to exponentially growing computational costs and reachability deficits for noisy intermediate-scale quantum (NISQ) devices. This study focuses on the multiscale quantum approximate optimization algorithm (MQAOA), which integrates renormalization group (RG) transformations with QAOA to address these limitations. Based on the connections between the variables in the problem to be solved, the weighted maximal matching method is employed to generate a variable partitioning strategy guiding the RG transformation. This approach not only extends the applicability of MQAOA to satisfiability (SAT) problems - including those with three-body and higher-order interactions in the problem Hamiltonian - but also eliminates the algorithm's sensitivity to problem density. Validations conducted on quantum simulators show that, after running two-round MQAOA, its capability is enhanced to identify optimal solutions with approximately 97% success probability as defined by the ground-state overlap for Max-2-SAT problems (78% success probability for Max-3-SAT problems). The results confirm the feasibility of MQAOA and establish it as a resource-efficient framework for complex combinatorial optimization problems, providing a pathway for NISQ-era deployment.

Three-party semi-quantum dialogue enhanced with Grover’s algorithm based encoding and hypergraph access control

Rui Tao(陶瑞), Jin-Zhe Jiang(蒋晋喆), and Zhi-Hua Zhang(章志华)

Chin. Phys. B, 2026, 35 (7): 070306. DOI: 10.1088/1674-1056/ae7274

Abstract ( 31 )

PDF (363KB) ( 11 )

We introduce a new three-party semi-quantum dialogue (3P-SQD) protocol that combines GHZ-state-based semi-quantum communication, a Grover's algorithm-driven 2-bit encoding scheme, and hypergraph-based access control. In each round, the fully quantum participant Alice sends two bits, whereas the semi-quantum participants Bob and Charlie, restricted to semi-quantum operations such as measurements in the computational basis and reflection, each transmit one bit. The protocol incorporates probe state checking, Grover's algorithm-based encoding, and hypergraph-based authorization. It achieves information-theoretic security and controlled access, while preserving high message throughput and imposing no additional requirements on the semi-quantum users.

Three-party quantum key agreement with seven-particle entangled states against collective noise: IBM Qiskit implementation

She-Xiang Jiang(蒋社想) and Jin-Huan Li(李金欢)

Chin. Phys. B, 2026, 35 (7): 070307. DOI: 10.1088/1674-1056/ae53b6

Abstract ( 5 )

PDF (957KB) ( 0 )

Quantum key agreement (QKA) constitutes a vital branch of quantum cryptography, referring to the collaborative establishment of a shared key among multiple participants. Among these, the three-party quantum key agreement (TPQKA) represents a specific form of QKA involving only three participants. Quantum states inevitably suffer from noise during transmission through quantum channels, which reduces the efficiency of qubits. To significantly improve the efficiency of qubits and further enhance their reliability in quantum applications, this paper proposes two TPQKA protocols based on seven-particle entangled states to provide protection against collective noise effects. In this paper, IBM Qiskit is employed to present the preparation circuit of the seven-particle entangled state, as well as the quantum circuits under two types of collective noise. In both protocols, the three parties apply a hash function to their own keys. In the particle transmission process, according to the measurement results of the particles, the three parties perform the corresponding unitary operation, and ultimately they equally negotiate the final shared key. Both protocols are robust against collective noise, and their qubit efficiency reaches 19.35%. In addition, the security analysis shows that both protocols are resistant to participant attacks and outside attacks, including intercept-resend attacks and entangle-measure attacks. This paper details the detection method of eavesdropping by eavesdroppers in collective noise through simulation, and finally presents key post-processing.

Barocaloric effect and materials: A review

Zi-Qi Guan(关子奇), Chang-Jiang Bao(包长江), Ji-Wei Yao(姚继伟), Nan Zhou(周楠), Yuan-Wen Feng(冯远文), Hao-Yu Wang(王皓宇), Kun Zhang(张琨), and Bing Li(李昺)

Chin. Phys. B, 2026, 35 (7): 070501. DOI: 10.1088/1674-1056/ae53b2

Abstract ( 37 )

PDF (1588KB) ( 21 )

As the global energy crisis and environmental issues intensify, the development of efficient and environmentally friendly novel refrigeration technology has become a significant focus in the field of scientific research and engineering. Conventional vapor compression refrigeration utilizes vapor refrigerants with high global warming potentials, which not only consume huge amounts of energy but also adversely affect the environment. In recent years, solid-state refrigeration technology has emerged as a research hotspot because of its controllable refrigerants, high energy efficiency, and environmental friendliness. Among the various refrigeration technologies that yield caloric effects through external-field-induced phase transitions, barocaloric refrigeration technology has been highly anticipated due to its low required driving pressure for refrigerant materials, large entropic change upon phase transition, and potentially high efficiency. On the other hand, many types of barocaloric materials are currently available, including intermetallic compounds, inorganic and organic materials, as well as organic—inorganic hybrid materials. Based on the barocaloric effect mechanism and the fundamental principles of various barocaloric materials, this paper summarizes the latest research in this field. It reviews the origins of the caloric effects of different types of barocaloric materials. The future development directions and application prospects of barocaloric solid-state refrigeration technology and materials are outlined.

A feedback-controlled optoelectronic platform for programming interactions in active matter

Shutong Guo(郭姝彤), Zhiqing Huang(黄芷晴), Bingrui Xu(徐冰睿), Shuailong Zhang(张帅龙), and H. P. Zhang(张何朋)

Chin. Phys. B, 2026, 35 (7): 070502. DOI: 10.1088/1674-1056/ae6320

Abstract ( 26 )

PDF (1514KB) ( 3 )

Active matter systems involve complex interactions between constituent particles, often mediated by physical or chemical fields, and in some cases, governed by sensing or decision-making processes. Experimentally controlling such interactions remains highly challenging, posing a major obstacle to systematic investigation. In this work, we present an optoelectronic tweezer (OET) platform that uses closed-loop feedback to program both motion and interactions in colloidal systems by dynamically patterning local electric fields with light. Operating at very low optical intensities, this approach allows rapid and precise control over dielectrophoretic forces acting on colloidal particles. We demonstrate the capabilities of this platform through the experimental realization of both a programmable active Brownian particle system and a communicating active particle system. This versatile platform bridges theoretical models of active matter and their experimental realization, enabling direct control over propulsion and interaction rules.

Hybrid computational analysis of fractional optical soliton structures in a dispersive Schrödinger model with applications in nonlinear optics

Mati ur Rahman, Sonia Akram, and Laila A. AL-Essa

Chin. Phys. B, 2026, 35 (7): 070503. DOI: 10.1088/1674-1056/ae5808

Abstract ( 4 )

PDF (4390KB) ( 0 )

The present study aims to integrate and explore optical solitary wave solutions within the framework of the high-order fractional dispersive extended nonlinear Schrödinger model (FDENLSM), a refined mathematical formulation with wide-ranging applications in nonlinear physics, optical communications, and field theory. By utilizing three contemporary computational approaches, namely, the modified Sardar sub-equation method, the new Kudryashov approach, and the improved F-expansion method, we obtain and systematically analyze a rich spectrum of optical soliton structures, including dark, singular, bright, periodic, exponential, rational, and composite forms. Furthermore, distinct wave patterns such as W-shaped, bell-shaped, peakon, and mixed trigonometric-hyperbolic solitons are also investigated. The study extends to the examination of modulation instability and gain spectra of the FDENLSM, providing deeper insight into the system's nonlinear characteristics. To vividly signify the obtained results, contour and density maps are presented in both two- and three-dimensional perspectives. The outcomes of this research contribute significantly to the understanding of complex nonlinear propagation phenomena, offering valuable analytical tools for researchers working in plasma dynamics, fiber optics, and related nonlinear systems.

A modular-bias-sin chaotification method for enhanced discrete memristor chaotic maps

Shu Yi(易澍), Huihai Wang(王会海), and Kehui Sun(孙克辉)

Chin. Phys. B, 2026, 35 (7): 070504. DOI: 10.1088/1674-1056/ae181e

Abstract ( 12 )

PDF (1256KB) ( 1 )

This paper proposes a novel modular-bias-sin chaotification method (MBSC) to address the limitations of existing discrete memristor (DM)-based chaotic maps. By applying MBSC to several fundamental discrete memristors, the enhanced chaotic variants are constructed. Comprehensive dynamical analyses, including attractor phase diagrams, Lyapunov exponents, bifurcation diagrams, Shannon entropy (SE) complexity, and chaotic region scale (CRS), demonstrate that the MBSC-enhanced maps outperform the original DM maps and existing modified models. Specifically, they exhibit wider chaotic parameter ranges, larger Lyapunov exponents, higher SE complexity, and robust hyperchaotic behavior. To validate practical applicability, a pseudo-random number generator (PRNG) based on the enhanced chaotic maps is implemented, which passes all NIST SP 800-22 statistical tests, confirming its high randomness and suitability for security-sensitive applications.

Curvature-driven shifts of the Potts transition on spherical Fibonacci graphs: A graph-convolutional transfer-learning study

Zheng Zhou(周政), Xu-Yang Hou(侯旭阳), and Hao Guo(郭昊)

Chin. Phys. B, 2026, 35 (7): 070505. DOI: 10.1088/1674-1056/ae6637

Abstract ( 19 )

PDF (4384KB) ( 4 )

We investigate the ferromagnetic $q$-state Potts model on spherical Fibonacci graphs. These graphs are constructed by embedding quasi-uniform sites on a sphere and defining interactions via a chord-distance cutoff chosen so as to yield a network approximating four-neighbor connectivity. By combining Swendsen-Wang cluster Monte Carlo simulations with graph convolutional networks (GCNs), which operate directly on the adjacency structure and node spins, we develop a unified phase-classification framework applicable to both regular planar lattices and curved, irregular spherical graphs. Benchmarks on planar lattices demonstrate an efficient transfer strategy: after a fixed binarization of Potts spins into an effective Ising variable, a single GCN pre-trained on the Ising model can localize the transition region for different $q$ values without retraining. Applying this strategy to spherical graphs, we find that curvature- and defect-induced connectivity irregularities induce only modest shifts in the inferred transition temperatures relative to their planar counterparts. Further analysis shows that the curvature-induced shift of the critical temperature is most pronounced at small $q$ and diminishes rapidly as $q$ increases. This trend is consistent with the physical picture that, in two dimensions, the Potts model undergoes a transition from a continuous phase transition to a weakly first-order one for $q$>4, accompanied by a pronounced reduction in the correlation length.

Noise evaluation and optimization for a cryogenic sapphire oscillator with 10^-15 level stability

Encai Zhong(钟恩才), Yan Zheng(郑琰), Hongli Liu(刘洪力), Mingming Liu(刘明明), Jinxu Hong(洪金旭), Yijun Luo(罗逸骏), Ke Deng(邓科), Jie Zhang(张洁), and Zehuang Lu(陆泽晃)

Chin. Phys. B, 2026, 35 (7): 070601. DOI: 10.1088/1674-1056/ae53ba

Abstract ( 9 )

PDF (2565KB) ( 0 )

Cryogenic sapphire oscillators (CSOs) simultaneously achieve ultra-low phase noise and outstanding frequency stability, making them widely used in precision measurement applications. In this study, performance evaluation and noise analysis are conducted on a home-built CSO. When compared with an optically generated microwave (OGM) reference, its synthesized 100 Hz signal demonstrates a relative frequency instability (Allan deviation) of $2.1\times {10}^{-15}$ at an averaging time of 70 s. After evaluation of the dominant noise sources, it is shown that the short-term frequency stability is limited by the 1.4 Hz vibrational noise from the pulse cryocooler, resulting in a limitation of $1.2\times 10^{-15}$ $\tau^{-1}$. At an averaging time of 100 s, the contribution of temperature fluctuation noise becomes prominent, limiting the frequency stability to 10$^{-16}$. In the long term, the stability of the voltage reference in the microwave power servo becomes the limiting factor. This research provides guidelines for the development of improved CSOs and their further applications in precision measurement physics.

Electrocaloric thermal management devices: Toward high-efficiency solid-state refrigeration

Yiwen Bo(薄轶文) and Rujun Ma(马儒军)

Chin. Phys. B, 2026, 35 (7): 070701. DOI: 10.1088/1674-1056/ae3309

Abstract ( 24 )

PDF (770KB) ( 5 )

Addressing the urgent demands for intelligent, miniaturized, and efficient thermal management in modern electronics, alongside the energy and environmental constraints, the development of compact and high-performance cooling systems has become imperative. The electrocaloric (EC) effect, which enables reversible entropy and temperature changes in dielectric materials through electric-field-controlled polarization, offers distinct advantages including high efficiency, fast response, and ease of integration. This review outlines the thermodynamic principles and surveys the evolution of EC thermal management devices. Ceramic-based EC devices exhibit strong potential for high-power applications due to their high thermal conductivity and thermal stability, while polymer-based EC devices are suited for wearable and flexible integration because of their mechanical compliance and processability. This review further contrasts the design, actuation, and application profiles of these platforms. Despite notable progress, challenges remain in long-term stability, multi-physics coupling, miniaturized integration, and environmental adaptability. Advances in material understanding, device design, and intelligent system control will position EC technology as a key enabler of efficient, compact, and sustainable next-generation thermal management.

Polymer nanocomposites for electrocaloric refrigeration: Applications and research advances

Hongtian Li(黎洪天), Feifan Yang(杨非凡), Shenglin Jiang(姜胜林), Kanghua Li(李康华), and Guangzu Zhang(张光祖)

Chin. Phys. B, 2026, 35 (7): 070702. DOI: 10.1088/1674-1056/ae48ba

Abstract ( 29 )

PDF (897KB) ( 6 )

With the global surge in refrigeration demand, developing efficient, environmentally friendly solid-state refrigeration technologies is urgent. Polymer materials leveraging the electrocaloric effect (ECE) are promising alternatives to traditional vapor compression refrigeration, due to their zero global warming potential and flexibility. This review summarizes progress in polymer-based electrocaloric (EC) material composites from material design to device integration, emphasizing multiscale synergistic design as the core strategy to address polymers' inherent low thermal conductivity and high operating electric fields. We discuss ECE regulation mechanisms and synergistic effects across scales: molecular (defect engineering, high-entropy design), mesoscale (interface engineering), and macroscale (film thickness, external field control). Key challenges (low thermal conductivity, high operating fields) are analyzed, and future work should focus on precise interface engineering and multiscale structural design to advance polymer electrocaloric coolers from lab to commercialization.

ALSS: Apparatus for the loading of sublimable systems

Yuchen Ye(叶育辰), Huixin Hu(胡蕙昕), Jin Zhang(张锦), Francesco Capitani, Mario Santoro, Federico Gorelli, and Philip Dalladay-Simpson

Chin. Phys. B, 2026, 35 (7): 070703. DOI: 10.1088/1674-1056/ae60f2

Abstract ( 16 )

PDF (1380KB) ( 4 )

A system for the loading of sublimable systems at 0 ℃ into a versatile membrane/screw-actuated symmetric diamond anvil cell (DAC) has been developed. This system, known as the Apparatus for the Loading of Sublimable Systems (ALSS), has the unique incorporation of an internal membrane, which acts against the clamping force of the screws. Through the inflation/deflation of the internal membrane, it is possible to open and close the cell under a pressurized environment without the need to maintain pressure differentials and/or high-pressure mechanical feedthroughs. Here, we present an overview of ALSS and its application in loading sulfur hexafluoride (SF₆) and carbon dioxide (CO₂), including the first infrared absorption measurements of SF₆ up to 50 GPa.

A dual-Helmholtz-coil magnetic field system for polarized ³He

Jian Tang(唐健), Zecong Qin(秦泽聪), Yunfei Li(李云飞), Long Tian(田龙), Bin Wang(王斌), Qingbo Zheng(郑清波), Yujie Zheng(郑玉杰), Junsong Xie(谢俊松), Han Gao(高寒), Yuan Yao(姚远), Jun Li(李君), Tianhao Wang(王天昊), Junpei Zhang(张俊佩), and Xin Tong(童欣)

Chin. Phys. B, 2026, 35 (7): 070704. DOI: 10.1088/1674-1056/ae4580

Abstract ( 44 )

PDF (1537KB) ( 11 )

This study focuses on developing a dual-Helmholtz-coil magnetic field system for polarized $^3$He to generate a uniform magnetic field. A theoretical analysis of the mechanism by which dual Helmholtz coils produce a uniform magnetic field was first conducted. Based on these findings, the magnetic device was designed with the finite element analysis software COMSOL, employing an optimization algorithm to efficiently set current densities and minimize the transverse gradient in the central region. The simulated transverse gradient achieved was 9.54$\times10^{-5}$ cm$^{-1}$ in the 20 cm$\times$20 cm$\times$8 cm central region, and the experimental measurement yielded a value of 6.31$\times10^{-4}$ cm$^{-1}$. Additionally, lifetime testing of two polarized $^3$He cells revealed lifetimes of 151.0$\pm$1.8 h and 206.2$\pm$4.4 h, demonstrating the excellent magnetic field uniformity of the device. The current work integrates theoretical, simulated, and experimental results. It advances polarized $^3$He magnetic technology, offers an upgrade solution for off situ polarized $^3$He pumping stations to extend the volume of the uniform magnetic field without enlarging the coil size, and provides a method for using polarized $^3$He on neutron beamlines requiring large acceptance angles.

Multi-task deep-learning optimization of trade-off properties for superior-performance Fe-based soft magnetic alloys

Kang-Yuan Li(李康源), Mao-Zhi Li(李茂枝), and Wei-Hua Wang(汪卫华)

Chin. Phys. B, 2026, 35 (7): 070705. DOI: 10.1088/1674-1056/ae5b5f

Abstract ( 5 )

PDF (2211KB) ( 1 )

Fe-based amorphous alloys are promising soft magnetic materials for developing next-generation devices with high frequency and efficiency. However, optimizing Fe-based alloys with ultra-high saturation magnetic flux density ($B_{{\rm s}}$), ultra-low coercivity ($H_{{\rm c}}$), and good glass-forming ability remains a notorious challenge owing to the vast composition space and complex trade-offs among these properties. Thus, conventional design methods face great challenges. Here, we develop a generative multi-task deep learning (GMTDL) approach to achieve simultaneous optimization of compositions and trade-off properties. The GMTDL can sufficiently exploit and share knowledge from datasets across different tasks, despite the limitations and imbalances of these datasets. Therefore, it exhibits superior performance in predicting alloys with multiple targeted properties, outperforming previous machine learning-based design strategies. Moreover, the GMTDL can also tailor compositions, providing an efficient way to regulate properties and generate desired candidates for further experimental processing. The validity and reliability of GMTDL are rigorously tested by benchmarking against Fe-based alloys reported very recently. Moreover, some new alloys with ultra-high $B_{{\rm s}}$ and ultra-low $H_{{\rm c}}$ are predicted. The optimal content windows of key elements and their synergistic effects are also unraveled, providing practical guidance. Thus, our study establishes an effective and reliable paradigm for simultaneous prediction and optimization of high-performance materials with multiple properties.

Vector-total field magnetometry and calibration using NV center ensembles

Kai-Hui Wang(王凯辉), Yun-Bin Zhu(朱云彬), Zi-Yun Yu(于子云), Xiang Li(李想), Xiang-Mei Xu(许祥妹), Zhao Zhao(赵昭), Liang Zhang(张亮), Ke Jing(靖克), and Yi-Jin Xie(谢一进)

Chin. Phys. B, 2026, 35 (7): 070706. DOI: 10.1088/1674-1056/ae12d5

Abstract ( 13 )

PDF (2381KB) ( 3 )

Given the limitations in payload capacity and power availability on spacecraft, magnetometers capable of measuring both the vector and total magnetic fields are especially valuable for their compact and versatile design. Nitrogen-vacancy (NV) center ensembles offer precise vector magnetic field measurement capabilities, making them promising candidates for spaceborne magnetic sensing technologies. Here, we develop a technique to validate the vector-total field measurement accuracy performed by NV center ensembles. The validation procedure employs a turntable to simultaneously calibrate the bias magnetic field and quantify the uncertainty associated with total magnetic field measurements. Validation tests conducted in a geomagnetic field environment reveal a measured standard deviation of 0.1 μT, which is $0.2%$ relative to the geomagnetic field. With further refinement, the accuracy of total magnetic field measurements may improve to better than 0.01%. These results provide a valuable reference for the further development of vector-total field magnetometers and hold potential for applications in spacecraft.

Influence of silicon ion implantation on the morphological features, structural properties, optical, and electrical behavior of CR-39 polymers

Bashir S, Ahmad S, Ali N, Umm-i-Kalsoom, Rafique M S, and Husinsky W

Chin. Phys. B, 2026, 35 (7): 070707. DOI: 10.1088/1674-1056/ae39db

Abstract ( 19 )

PDF (3199KB) ( 2 )

The variations in morphological features, structural properties, optical characteristics, and electrical behavior induced by 610-keV Si ions in the CR-39 matrix have been investigated in the current research work. Polymer targets were irradiated with Si ions for various fluences spanning from $5\times 10^{13}$ ions/cm$^{2}$ to $35 \times 10^{16}$ ions/cm$^{2}$. The implantation of ions in the polymeric target generally leads to chain scission, bond breaking, and cross-linking, along with the formation of free radicals and ions. To confirm these effects, various characterization techniques have been utilized. Optical microscopy reveals the creation of micro-cavities and cracks along the grain boundaries. Confocal microscopy demonstrates the formation of micro-sized hillocks. The formation of SiC phase at 890 cm$^{-1}$ following ion implantation was identified by Raman spectroscopy. Furthermore, in CR-39, a significant reduction in optical transmittance in the visible region is attributable to the formation of Si and carbonaceous clusters on the target surface. The enhancement in the electrical conductivity of the Si ion implanted polymer with an increase in ion fluence is attributable to fine crystallinity and the development of SiC bridges. The assessed temperature of the surface of the implanted polymer ranges from $2.2 \times 10^{4}$ K to $6.2 \times 10^{4}$ K. The LET (total linear energy transfer) value of 610-keV implanted ions and their depth are 63 eV/Å and 1.11 μm recorded in CR-39, respectively, estimated by SRIM simulation. The improved morphological features, structural properties, optical characteristics, and electrical behavior of CR-39 make it beneficial for applications in packaging and electronic industries, medical sciences, and photonic devices.

Effect of hydrogen bond site on proton irradiation of guanine-cytosine base pair: A real-time first-principles study

Chao-Yi Xue(薛超怡), Zhihua Hu(胡志花), Xin Wang(王欣), Ming-Zi Wang(王明梓), and Hong-Jian Feng(冯宏剑)

Chin. Phys. B, 2026, 35 (7): 073101. DOI: 10.1088/1674-1056/ae118c

Abstract ( 13 )

PDF (753KB) ( 2 )

Ion beam irradiation is widely used in radiotherapy and radiation protection. Investigating hydrogen bond site effects on DNA ionization under proton irradiation is crucial for understanding DNA damage mechanisms. We use real-time time-dependent density functional theory (rt-TDDFT) to establish guanine-cytosine (GC) base pair models and investigate their ionization damage processes under proton irradiation with different hydrogen bond positions in this study. By tracking the deposition energy, electronic stopping power (ESP), atomic forces, charge density, and excited electrons, we explore the impact of hydrogen bond positions on GC base pair ionization damage. The analysis indicates that, compared with the configurations of hydrogen bonds, the hydrogen bond donor (cytosine for LHB, guanine for MHB and RHB) cannot be ignored. Our findings offer important insights into the ionization mechanism and damage processes of DNA molecules during ion beam irradiation, which can guide applications in radiotherapy and radiation protection.

Relativistic many-body calculations of multipole (E1, M1, E2, M2) transition properties in Al II

Yuan-Fei Wei(魏远飞), Zhi-Ming Tang(唐志明), Xue-Ren Huang(黄学人), Ming-Lu Bu(布明鹭), Xin-Ye Xu(徐信业), and Yi-Yu Cai(蔡翊宇)

Chin. Phys. B, 2026, 35 (7): 073102. DOI: 10.1088/1674-1056/ae0d77

Abstract ( 23 )

PDF (857KB) ( 11 )

We present systematic relativistic many-body calculations of multipole transition properties for singly charged aluminum ion (Al II) using a method that combines configuration interaction and many-body perturbation theory ($\rm CI+MBPT$). Our calculations cover the 103 lowest energy levels in Al II. For five key low-lying states (3s$^{2}$ $^{1}$S$_{0}$, 3s3p $^{3}$P$_{0}$, 3s3p $^{3}$P$_{1}$, 3s3p $^{3}$P$_{2}$, and 3s3p $^{1}$P$_{1}$), we tabulate the transition wavelengths, reduced matrix elements, transition probabilities, and oscillator strengths for about 400 electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2), and magnetic quadrupole (M2) transitions arising from these levels. Our calculated values agree well with available experimental data and other high-precision theoretical calculations, with typical deviations on the order of 1%. Notably, we report over 80% of these transition lines as previously unreported, significantly expanding the existing spectroscopic database for Al II. These results can serve as a valuable reference resource for ongoing precision quantum metrology as well as astrophysical spectroscopy involving the Al II ion.

Manipulations of atomic below-threshold harmonic generation by electrostatic fields

Junyong He(何俊泳), Shilin Hu(胡师林), Pengcheng Li(李鹏程), and Jing Chen(陈京)

Chin. Phys. B, 2026, 35 (7): 073103. DOI: 10.1088/1674-1056/ae7db7

Abstract ( 21 )

PDF (360KB) ( 10 )

We have studied the harmonic spectra of hydrogen atoms subjected to different combined laser fields with increasing electrostatic fields, which are based on the numerical solutions of the time-dependent Schrödinger equation. It is found that, as the electrostatic field increases, a hump structure in the below-threshold harmonic spectra will show up. The reasons are that the below-threshold harmonic generation is closely related to the excited states, and the probabilities of the excited states 2s and 2p evidently increase with the increasing electrostatic fields.

Spectroscopic study of odd-parity excited levels of atomic gadolinium in the 28700-31500 cm^-1 region using a three-color three-step resonance ionization pathway

Jun-Yao Zhang(张钧尧), Kai-Chen Ma(马恺宸), Jing-Yi Xiong(熊静逸), Li-De Wang(王立德), Cai-Hua Zhu(朱才华), Jun-Jie Chai(柴俊杰), and Yun-Fei Li(李云飞)

Chin. Phys. B, 2026, 35 (7): 073201. DOI: 10.1088/1674-1056/ae12dd

Abstract ( 16 )

PDF (632KB) ( 1 )

The three-color, three-step resonance ionization spectroscopy technique was employed to investigate the odd-parity excited states of gadolinium in the 28700-31500 cm$^{-1}$ energy region. Spectra scanned without $\lambda _1$ led to the identification of 101 interference peaks, which were excluded from subsequent studies. A total of 40 odd-parity excited states were observed from scans of nine even-parity lower levels, including 19 states reported here for the first time. Unique $J$ values were assigned to 39 levels using the electric dipole selection rule. Comparison with previous studies confirms the reliability of the present results, with the absolute energy accuracy estimated to be better than $\pm 0.1$ cm$^{-1}$.

Absolute differential cross sections for low-energy He⁺-He collisions via fully quantum dynamics

Yu Wang(王瑜), Kun Wang(王堃), Yu-Kun Yang(杨玉坤), Chuan-Liang Li(李传亮), Ling Liu(刘玲), Yong Wu(吴勇), Svetlana A. Yakovleva, and Andrey K. Belyaev

Chin. Phys. B, 2026, 35 (7): 073401. DOI: 10.1088/1674-1056/ae64d6

Abstract ( 22 )

PDF (950KB) ( 4 )

Angular differential cross sections for elastic scattering and charge transfer in low-energy He$^+$-He collisions underpin diverse plasma applications, yet systematic quantum mechanical data remain scarce. Employing the fully quantum mechanical molecular-orbital close-coupling method with high-accuracy ab initio potential energy curves, absolute angular differential cross sections are computed over 0.005-1250 eV/u and scattering angles 0.01$^\circ$-90$^\circ$. The present results show good agreement with available high-resolution experimental benchmarks in both magnitude and oscillatory structure, with improved consistency over existing semiclassical and single-electron approaches. By decomposing the cross sections into separate symmetric and antisymmetric channel contributions, three classes of oscillatory structures and their energy evolution are identified: regular oscillations from two-channel quantum interference, irregular oscillations from rainbow scattering in the deep attractive well, and fine-scale oscillations from matter-wave diffraction off the repulsive wall. This work provides the first systematic, fully quantum mechanical differential cross-section dataset across the low-energy and full angular range, serving as reliable reference data for plasma modeling and related applications.

Spin- and state-resolved charge transfer and excitation in low-energy He⁺-Na(3s,3p) collisions

Xiao-Xia Wang(王小霞), Rui Tang(唐瑞), Li Ma(马丽), Chuan-Yu Zhang(张传瑜), Jian-Guo Wang(王建国), and Yi-Zhi Qu(屈一至)

Chin. Phys. B, 2026, 35 (7): 073402. DOI: 10.1088/1674-1056/ae705c

Abstract ( 20 )

PDF (973KB) ( 3 )

We present a theoretical study of charge-transfer (CT) and electron-excitation (EX) processes in collisions of He$^+$ with Na(3s) and Na(3p) using the quantum-mechanical molecular-orbital close-coupling (QMOCC) method. Adiabatic potential curves together with the corresponding radial and rotational nonadiabatic couplings are calculated for both singlet and triplet spin manifolds. State-resolved results show that, for He$^+$-Na(3s) collisions, the CT process is mainly governed by long-range Demkov-type interactions, with electron capture predominantly populating the He(1s2s) triplet state, while excitation cross sections are smaller and occur at shorter internuclear distances. In the He$^+$-Na(3p) system, additional $\Pi$-symmetry channels participate in the dynamics, leading to dominant capture into the He(1s2p) state. Despite the different initial electronic configurations, the total CT cross sections for Na(3p) are comparable in magnitude to those for Na(3s), with $\Sigma $-symmetry channels contributing more efficiently than $\Pi $ channels. The calculated total CT cross sections for Na(3s) and Na(3p) are on the order of $10^{-18}$-$10^{-14}$ cm$^2$ and agree with the experimental data within deviations of about 5% and 10%-20% in the overlapping energy range. The present results show good agreement with available experimental and theoretical data, providing a comprehensive description of the state-resolved collision dynamics in the low- and intermediate-energy regimes.

Pre-emptive parametric kill switch for evaporative atomic sources in vacuum

Shuang Li(李爽), Zhiyuan Lin(林志远), Sen Li(李森), Mohan Zhang(张默含), Fengquan Zhang(张凤泉), Jin Hu(胡瑾), Xiaotong Liu(刘宵彤), Lin Meng(孟林), Tim Byrnes, and Valentin Ivannikov(瓦伦丁)

Chin. Phys. B, 2026, 35 (7): 073701. DOI: 10.1088/1674-1056/ae577f

Abstract ( 6 )

PDF (958KB) ( 0 )

A robust pre-emptive kill switch for cold atom experiments is introduced to significantly reduce costly system reassembly or replacement. The design incorporates upper (alarm) and lower (evaporation) event detection mechanisms based on predefined thresholds. Meanwhile, a duty cycle timing methodology is employed to prevent unintentional activation of the dispenser when pulse signals occur. The circuit employs generic components, a modular design, and formalized logic, ensuring cost-effectiveness and making the design suitable for school laboratories and other research environments. This design is highly versatile and can be applied to other sensitive devices beyond dispensers, such as heating filaments, titanium sublimation pumps, tungsten lamps, and comparable systems.

Sensitive sensing based on quantum correlation of photons in weak nonlinear regime

Zi-Qiang Yin(尹子强), Zhi-Hao Liu(刘志豪), Jian Tang(唐健), Hui Jing(景辉), and Xun-Wei Xu(徐勋卫)

Chin. Phys. B, 2026, 35 (7): 074201. DOI: 10.1088/1674-1056/ae5c71

Abstract ( 43 )

PDF (1385KB) ( 16 )

Quantum correlation of photons based on quantum interference, such as unconventional photon blockade (UPB), has been extensively studied for realizing single-photon sources in a weak nonlinear regime. However, how to use this effect for other practical applications is rarely studied. Here, we propose to realize angular velocity and temperature sensing based on the quantum correlation of photons induced by quantum interference. We demonstrate that UPB can be observed in the mixing field output from a Mach—Zehnder interferometer (MZI) with two cavities in its two arms based on quantum interference. We show that the second-order correlation function of the output field is sensitive to the parameters of the system, and propose schemes to realize angular velocity and temperature sensing by measuring the second-order correlation of the photons output from the MZI. We find that the second-order correlation function of the output field is much more sensitive to the parameters of the system than the mean photon number, which provides an application scenario for UPB in sensitive sensing.

Dual-wavelength femtosecond Tm: LuYO₃ ceramic laser in-band pumped by 1650 nm Er:YAG laser

Jinfang Yang(杨金芳), Purui An(安浦瑞), Chao Bi(毕超), Taotao He(何涛涛), Shichao Yuan(袁诗超), Xinye Tian(田新叶), Man Wan(汪满), Yongle Zhu(朱永乐), Zhong Dong(董忠), and Weijun Ling(令维军)

Chin. Phys. B, 2026, 35 (7): 074202. DOI: 10.1088/1674-1056/ae1fe4

Abstract ( 28 )

PDF (466KB) ( 9 )

An in-band pumped dual-wavelength femtosecond Tm:LuYO$_{3}$ ceramic laser is demonstrated for the first time, to the best of our knowledge. In the continuous wave (CW) regime, a maximum output power of 1.03 W with a slope efficiency of 28.7% is obtained; the center wavelength can be independently tuned within the range of 1962 nm to 2070 nm using output couplers (OCs) with different transmittance rates. A single-wavelength laser at 2059 nm is achieved with the shortest pulse duration of 313 fs, a maximum average output power of 374 mW, and operating at a repetition rate of 93.13 MHz. Using a 3% OC, dual-wavelength femtosecond pulses at 1950 nm and 2047 nm were simultaneously generated. Furthermore, the phenomenon of wavelength redshift was observed as the pump power was increased. These experimental results indicate that in-band pump technology combined with Tm:LuYO$_{3}$ ceramics could be a potential means to reduce the thermal effect and scale the output power and conversion efficiency for 2 μm ultrafast lasers.

Transfer of Fisher information in quantum postselection metrology

Zi-Rui Zhong(钟子瑞), Ke-Xuan Chen(陈可轩), Xia-Lin Su(苏夏临), Hui-Lin Xu(徐惠林), Yan Zhang(张妍), Xiang-Ming Hu(胡响明), and Qing-Lin Wu(吴青林)

Chin. Phys. B, 2026, 35 (7): 074203. DOI: 10.1088/1674-1056/ae194f

Abstract ( 18 )

PDF (636KB) ( 6 )

Postselected weak measurement has shown significant potential for detecting small physical effects due to its unique weak-value-amplification phenomenon. Previous works suggest that Heisenberg-limit precision can be attained using optical coherent states. However, the observed Heisenberg scaling requires a measurement of the distribution of postselection probability, exhibiting no implementation pathway through conventional measurement paradigms. Here, we demonstrate that the output photons can also reach the Heisenberg scale by utilizing the Fisher information transfer effect, while this scenario exhibits enhanced robustness against dephasing noise. In addition, we consider the insertion of a power-recycling cavity and demonstrate its positive impact on the distribution of postselection. Our results enhance the quantum metrological advantages of the postselection strategy and broaden its application scope.

Three-dimensional frequency-wavenumber method for efficient and high-quality volumetric ultrasound imaging

Huchang Guan(关虎昌), Chen Jiang(江晨), Kailiang Xu(许凯亮), and Dean Ta(他得安)

Chin. Phys. B, 2026, 35 (7): 074301. DOI: 10.1088/1674-1056/ae42b9

Abstract ( 3 )

PDF (10931KB) ( 0 )

Total focusing method (TFM) using full matrix capture (FMC) data provides high-quality ultrasound imaging by enabling pixel-level dynamic focusing during both transmission and reception. However, when applied to three-dimensional (3D) ultrasound imaging with a two-dimensional (2D) matrix array (MA), TFM suffers from computational inefficiency due to the conventional delay-and-sum (DAS) algorithm, which limits its applicability in high-volume imaging scenarios. To address this challenge, we introduce an efficient beamforming framework, designated MA-FMC-fk, leveraging the frequency-wavenumber ($f$-$k$) domain to accelerate 3D FMC imaging. The proposed method achieves a computational complexity of $O(N_u^2 N_v^2 N_z \log_2(N_u^2 N_v^2 N_z))$, compared to $O(N_u^2 N_v^2 N_z N_x N_y)$ for the conventional DAS algorithm. The imaging performance of the proposed method was evaluated using simulations, phantom experiments, and in-vivo studies. Quantitative results demonstrate that MA-FMC-fk improves the average lateral resolution by 25.00% for the simulated point targets and by 19.18% for the phantom wire experiments compared to the DAS algorithm. In addition, MA-FMC-fk enhances the average contrast-to-noise ratio (CNR) by 11.73% and the speckle signal-to-noise ratio (sSNR) by 11.16% for the phantom cyst. The MA-FMC-fk algorithm achieves a several-fold reduction in computation time on a CPU-based MATLAB platform relative to DAS. The human experimental results further demonstrate the effectiveness of the proposed method, in which the sSNR and CNR are improved by 19.74% and 18.18%, respectively. The results demonstrate that the MA-FMC-fk method improves image quality while reducing computational cost for 3D TFM imaging using a 2D matrix array.

Enhanced ultrasonic scalpel in longitudinal-bending coupled vibration based on symmetrical acoustic black hole beam structure

Cheng Chen(陈诚), Yi Wang(王怡), Huiqin Chen(陈慧琴), Chunlong Xu(徐春龙), Jianzhong Guo(郭建中), and Shuyu Lin(林书玉)

Chin. Phys. B, 2026, 35 (7): 074302. DOI: 10.1088/1674-1056/ae1b7a

Abstract ( 12 )

PDF (1703KB) ( 2 )

Modern minimally invasive and robotic intelligent surgeries require the miniaturization of ultrasonic scalpels (USs), resulting in a compromise in performance, which is currently an urgent technological challenge needing a breakthrough. Additionally, acoustic black holes (ABHs) have attracted widespread attention for their unique ability to capture and focus waves. Hence, a novel enhanced ultrasonic scalpel (EUS) based on symmetrical ABH beam structure in coupled vibration is proposed, capable of achieving strong, cumulative amplification of the amplitude on a short blade and effectively mitigating the performance loss caused by miniaturization. Through numerical modeling, the longitudinal and bending vibration modes of the EUS are coupled at the same frequency by adjusting the blade size. Theoretical modeling results preliminarily verify the design feasibility of the simulation and explain the physical mechanism by which the ABH effect enhances the EUS. Experimental results demonstrate that the EUS achieves a maximum vibration displacement nearly 400% greater than that of the conventional ultrasonic scalpel (CUS), along with the capability for two-dimensional cutting. This research provides theoretical and experimental references for the development of high-performance ultrasonic medical devices and explores the potential applications of ABHs in ultrasonic technology.

Finite temperature Casimir effect of scalar field

Liang Chen(陈亮), Yu-Jing Wang(王钰婧), and Sheng-Yan Li(李生艳)

Chin. Phys. B, 2026, 35 (7): 074401. DOI: 10.1088/1674-1056/ae24ea

Abstract ( 14 )

PDF (1511KB) ( 0 )

We derive analytical expressions for the Helmholtz free energy, Casimir force, and Casimir entropy in one- and three-dimensional scalar fields subject to Dirichlet boundary conditions at finite temperature. The problem of negative Casimir entropy is examined in these systems, as well as for a scalar field confined within a three-dimensional (3D) spherical cavity. Our analysis shows that this apparent paradox arises under different regularization schemes involving distinct counterterms. We advocate against introducing any counterterms for the thermal corrections to the Casimir effect and predict that the thermal-fluctuation-induced Casimir force becomes repulsive in the high-temperature limit, specifically when $aT/(\pi\hbar{v})>0.2419$ for the 3D scalar field.

Phase encoding in parametric nanomechanical resonator via annealing

Chen Yang(杨晨), Feng-Nan Chen(陈凤楠), Bo Wu(吴博), Ting-Ting Li(李婷婷), Zong-Yi Bao(鲍宗壹), Joel Moser, and Heng Lu(卢恒)

Chin. Phys. B, 2026, 35 (7): 074601. DOI: 10.1088/1674-1056/ae1def

Abstract ( 20 )

PDF (5377KB) ( 2 )

Nanomechanical resonators driven parametrically enable binary information encoding based on the control of their two possible vibrational phases. We present a protocol to flip the parametric phase in a graphene nanomechanical resonator via annealing, offering a novel approach to nanomechanical logic. The core of our methodology involves driving the resonator with a parametric excitation near twice its resonant frequency and applying an external drive to break the symmetry of the dynamical double-well potential of the bistable states. By introducing white force noise to anneal the resonator, its vibrational phase settles into the state with the lower potential. The phase can be deterministically prepared in one of two states, differing by approximately p radians, by controlling the phase of direct drive and annealing. The demonstrated protocol offers a promising approach for nanomechanical logic with potential advantages in efficiency, error resilience, and scalability.

Drift capability of swimming bacteria in shear flows

Fanglong Dang(党方龙), Wei Feng(冯伟), Xinlei Li(李欣蕾), Luo Hao(罗昊), Yanan Liu(刘亚楠), and Guangyin Jing(经光银)

Chin. Phys. B, 2026, 35 (7): 074701. DOI: 10.1088/1674-1056/ae40de

Abstract ( 15 )

PDF (1190KB) ( 6 )

The ability of microorganisms to control their swimming direction is crucial for navigating complex flow environments at low Reynolds numbers. We study how swimming Escherichia coli generate transverse locomotion across streamlines, defined as drift swimming, i.e., perpendicular to the flow direction, resulting from the chiral coupling between their flagellar rotation and an imposed shear flow. The drift velocity increases linearly with shear rate at low shear and saturates at a maximum value comparable to the intrinsic swimming speed. This maximum drift grows monotonically as cells approach the channel wall and is strongly enhanced under geometric confinement. Reorientation dynamics reveal a marginally stable fixed point along the vorticity axis, with oscillations around it arising from thermal noise and body–flagellum misalignment. Wall-induced hydrodynamic constraints suppress these fluctuations and amplify the drift. Our results demonstrate an enhanced navigation capacity under extreme shear relevant to bacterial colonization in confined environments.

Effect of a dynamic cooperative lane-changing algorithm on traffic evolution of connected and automated vehicles system at diverging on two-lane highways

Shuang Ren(任爽), Shuichao Zhang(张水潮), Huaqing Liu(刘华清), and Chen Zheng(郑晨)

Chin. Phys. B, 2026, 35 (7): 074702. DOI: 10.1088/1674-1056/ae27ae

Abstract ( 21 )

PDF (4319KB) ( 3 )

The diverging sections of two-lane highways are a typical traffic bottleneck in urban cities. Due to unregulated lane-changing (LC) behaviors, velocity oscillation and traffic congestion frequently occur. In this paper, a dynamic cooperative lane-changing (DCLC) algorithm is introduced to coordinate the LC behaviors of connected autonomous vehicles (CAVs) in a control zone upstream of the diverging point. For a CAV with LC demand, its virtual leader and follower on the adjacent lane are dynamically determined based on relative distances in real time. It will change lane if the safety time gap is satisfied. With the normal lane-changing algorithm as a benchmark, the phase transition and evolution of the traffic system are investigated and compared. Simulation results demonstrate that the proposed DCLC algorithm has a positive effect on traffic capacity. After the DCLC algorithm is implemented, the LC behaviors of CAVs are concentrated in the middle of the control zone, rather than being distributed near the diverging point in the benchmark. Moreover, some system characteristics have also been improved significantly. Finally, the sensitivities of demand and safety time gap in LC are analyzed to verify the universality of the DCLC algorithm in improving traffic performance.

Computational investigation on dynamics of atmospheric pressure air discharge excited by a twin needle-plate electrode configuration

Chang-Shuo Lv(吕长硕), Wen Yan(晏雯), Zhen-Hua Bi(毕振华), Ying Song(宋颖), Jin-Hai Niu(牛金海), and De-Zhen Wang(王德真)

Chin. Phys. B, 2026, 35 (7): 075101. DOI: 10.1088/1674-1056/ae1cb4

Abstract ( 14 )

PDF (1860KB) ( 3 )

The large-scale low temperature plasma produced by atmospheric pressure discharge utilizing an array needle-plate electrode design has promising future applications in a variety of industries. Improving the scale and uniformity of plasma requires a thorough investigation of the interactions between needle discharges. For that purpose, a two-dimensional (2D) computational analysis of the interaction of two concurrently propagating air discharges created by a twin needle-plate electrode design is presented in the paper. Investigations are also conducted on the effect of needle spacing, pulsed peak voltage, and pulse polarity. Immediately after ignition, two identical discharges move in the same direction toward the plane electrode. The propagation route is a curve with tight needle-to-needle spacing, which is ascribed to competition between electrostatic repulsion and photoionization-induced attraction. Larger needle spacing, higher peak voltage, or negative polarity all can increase the plasma area on the plate electrode. Additionally, reducing the distance between needles or raising the pulsed peak voltage is an effective way to improve the spatial homogeneity of the discharge array. Positive voltage pulses cause a more homogeneous discharge than negative voltage pulses.

Numerical studies on the linear and nonlinear evolutions of infernal modes

Jiu-Ying Li(李久瑛), Wei Zhang(张威), Zi-Xi Liu(刘子奚), Zhi-Wei Ma(马志为), Fei-Fei Long(龙飞飞), Cheng-Cheng Deng(邓成成), Peng-Cheng Li(厉鹏程), Kang-Ning Yang(杨康宁), Xiao-Yu Yin(尹晓宇), Run-Zhi Hu(胡润志), Yi-An Zhao(赵一安), Hong Li(李弘), Jin-Lin Xie(谢锦林), Tao Lan(兰涛), Wen-Zhe Mao(毛文哲), A-Di Liu(刘阿娣), Chu Zhou(周楚), Wei-Xing Ding(丁卫星), Ge Zhuang(庄革), and Wan-Dong Liu(刘万东)

Chin. Phys. B, 2026, 35 (7): 075201. DOI: 10.1088/1674-1056/ae1016

Abstract ( 17 )

PDF (3101KB) ( 2 )

The present paper numerically investigates the linear and nonlinear evolution of infernal modes through a three-dimensional, toroidal geometric, nonlinear, and full-MHD code CLT. For equilibria with $q_{{\min}}\approx $ 2.0, the development of the infernal modes leads to an elongated high-pressure region. We find that the nonlinear behaviors of the infernal modes can be totally different when the parallel thermal conductivity exceeds a threshold. Below this threshold, the infernal modes experience explosive growth in the nonlinear stage; above this threshold, they finally saturate in the nonlinear phase. For the cases with nonlinearly explosive growth, the patterns of the perturbed pressure are `ballooning-like' and the dominant modes are with $n> 1$, where n is the toroidal mode number. When the parallel thermal conductivity exceeds the threshold, the parallel diffusion along the magnetic field lines is quick enough. Then the nonlinearly explosive growth is suppressed, and the infernal modes will saturate in the nonlinear stage. A two-dimensional (2D) parameter map is provided to illustrate the transition between these distinct nonlinear regimes.

Numerical simulation of corona in electrical equipment operated at high altitude

Yue Zhang(张跃), Zhou Huang(黄洲), Xue-Ming Shen(沈雪明), Gen-Bo Zhang(张根博), and Wen-Jun Ning(宁文军)

Chin. Phys. B, 2026, 35 (7): 075202. DOI: 10.1088/1674-1056/ae1565

Abstract ( 17 )

PDF (1362KB) ( 2 )

Corona discharge is a common form of electrical fault in power equipment. Studying corona at different altitudes is essential for ensuring reliable operation of electrical systems under varying environmental conditions. In this work, a Multiphysics simulation model of corona discharge was developed to investigate the discharge behavior and induced ionic wind characteristics under different air pressures. First, the accuracy of the simulation model was validated by experiments. At 1 bar (1 bar = 10$^5$ Pa), Trichel pulses with an amplitude of 1.1 mA and a repetition frequency of 250 kHz were observed, along with a maximum ionic wind velocity of 9.49 m/s in the discharge channel. When the pressure was reduced to 0.79 bar, the discharge was overall enhanced, with the Trichel pulse amplitude decreasing to 0.5 mA, the repetition frequency increasing to 760 kHz, and the induced ionic wind becoming stronger. Both the velocity within the channel and the gap increased with decreasing pressure. This study provided a theoretical reference for the deployment and operation of electrical equipment in high-altitude environments

Spatiotemporal pulse-shaping effects on 4-μm laser-driven Sn microdroplet plasmas for extreme ultraviolet emission

Qi Min(敏琦), Chunbo Miao(苗春波), Hongyu Liu(刘宏宇), Xingbang Liu(刘兴邦), Haidong Lu(卢海东), Maogen Su(苏茂根), and Chenzhong Dong(董晨钟)

Chin. Phys. B, 2026, 35 (7): 075203. DOI: 10.1088/1674-1056/ae74c1

Abstract ( 36 )

PDF (660KB) ( 7 )

Drive lasers near the 4-μm wavelength offer a fundamental thermodynamic advantage for extreme ultraviolet (EUV) lithography by optimally balancing laser absorption and in-band EUV opacity. Using radiation-hydrodynamics simulations, we investigate spatiotemporal pulse-shaping effects on 4-μm-driven Sn microdroplet plasmas under an industrially relevant overfill geometry. An energy-conserved full-factorial strategy evaluates the independent influences of pulse duration, temporal envelope, and transverse spatial profile. Results reveal that temporal and spatial shaping govern distinct physical processes. Temporally, box-shaped profiles establish a quasi-steady-state hydrodynamic regime that sustains optimal ionization, preventing the severe over-ionization of high-peak Gaussian pulses and the under-heating of extended low-power pulses. Spatially, although transverse intensity variations negligibly impact macroscopic energy absorption, angular emission analyses demonstrate that flat-top beams uniformly ablate the target periphery. This suppresses the optically thick peripheral plasma shroud inherent to Gaussian beams, thereby minimizing angle-dependent self-absorption and enhancing isotropic EUV photon escape. Ultimately, combining a 15-ns box-shaped temporal envelope with a spatial flat-top profile achieves a maximum conversion efficiency of 3.35%. Thus, optimizing EUV emission requires utilizing temporal shaping to sustain intrinsic emissivity and spatial flattening to minimize radiation transport losses.

Development and performance of a micron-resolution neutron imaging detector at CSNS

Xing-Fen Jiang(蒋兴奋), Wen-Qin Yang(杨文钦), Jun-An Geng(耿君安), Sheng-Xiang Wang(王声翔), Xiao-Juan Zhou(周晓娟), Yan-Feng Wang(王艳凤), Jian-Rong Zhou(周健荣), Jie Chen(陈洁), Cheng-Hua Sun(孙承华), Zhi-Jia Sun(孙志嘉), and Yuan-Bo Chen(陈元柏)

Chin. Phys. B, 2026, 35 (7): 076101. DOI: 10.1088/1674-1056/ae5f05

Abstract ( 16 )

PDF (7707KB) ( 4 )

Neutron imaging is a powerful non-destructive testing technique, yet its spatial resolution remains considerably inferior to that of x-ray imaging. Bridging this resolution gap to the micron level represents a major challenge in the field. This study reports the development and performance of a micron-resolution neutron imaging detector at the China Spallation Neutron Source (CSNS). The detector consisted of a custom-fabricated, ultra-thin (5 μm) scintillator based on isotopically enriched gadolinium oxysulfide (¹⁵⁷Gd₂O₂S:Tb), coupled with a high-magnification optical lens and a scientific charge-coupled device (CCD) camera. At the Energy-Resolved Neutron Imaging Instrument (ERNI), the detector achieved a spatial resolution of 6.6 μm. The detector represents a significant leap in imaging capability at CSNS, enabling advanced non-destructive investigations at the microscale.

An efficient algorithm for generating perfect special quasirandom structures with many-body correlation functions and its application to the Kronig-Penney model

Tian-Ze Li(李天择), Chang-Chun He(何长春), and Xiao-Bao Yang(杨小宝)

Chin. Phys. B, 2026, 35 (7): 076102. DOI: 10.1088/1674-1056/ae69bf

Abstract ( 17 )

PDF (1556KB) ( 4 )

The special quasirandom structure (SQS) method provides an ideal representation of disordered structures. However, it is still a challenge to generate structures that perfectly satisfy the constraints of correlation functions, especially for many-body interactions. Taking one-dimensional systems as an example, we develop an efficient SQS construction algorithm for multi-component materials based on De Bruijn sequences, which can be extended to systems with higher dimensions and more components. The SQSs constructed by our algorithm are shown to universally satisfy all the constraints of 1 ~ n-body interactions, and the numbers of consecutive identical-atom subsequences follow a unified counting rule. Based on the Kronig–Penney model, we have systematically investigated the impact of structural disorder on electronic properties. As the cell size increases, there are the same trends in the electronic structures obtained from SQSs and fully random structures, while SQSs display markedly faster convergence and significantly reduced fluctuations. We demonstrate that SQS provides a reliable and efficient finite-size representation for electronic-structure calculations of disordered systems.

Minimum grain size and compression mechanical behavior of polycrystalline graphene based carbon honeycombs: Cell irregularity and grain size effect

Jing-Jing Xing(邢静静), Shunran Liu(刘顺然), Ren-Liang Zhang(张任良), Yong-Gang Wang(王永刚), and Li-Jun Yi(易利军)

Chin. Phys. B, 2026, 35 (7): 076103. DOI: 10.1088/1674-1056/ae12d1

Abstract ( 13 )

PDF (2175KB) ( 2 )

The graphene-based carbon honeycombs (CHCs) have excellent mechanical properties and various applications, and have attracted intensive attention recently. However, the real CHCs in experiments have random cell shapes. The effects of polycrystallinity and cell irregularity on the mechanical properties of CHCs are still unknown. Here, first, we investigate the minimum cell size stability with ideal cell walls in the polycrystalline graphene-based carbon honeycombs (PGCHs). Then, based on molecular dynamics simulations, the compressive mechanical properties of four PGCHs with typical cell irregularities are studied systematically, including the periodic regular graphene-based carbon honeycombs (RGCHs) with a zero-degree cell irregularity. Under in-plane compression, the Young's modulus, initial peak stress, mean plateau stress, and per volume energy absorption $W_{\rm v}$ of RGCHs and PGCHs decrease significantly with increasing grain size, and show a pseudo Hall-Petch relation. The mean plateau stress and $W_{\rm v}$ of PGCHs are higher than those of RGCHs. Under out-of-plane compression, the grain size effect is also obvious. However, the influence of cell irregularity is very small and can be ignored. The results indicate that the Hall-Petch relations of polycrystalline materials are dependent on both grain size and cell irregularity, and provide theoretical guidance for real CHCs in engineering applications.

Displacement damage effects of low-energy gallium ion irradiation on single-walled carbon nanotube field-effect transistors

Yu Zhang(张宇), Huanling Wang(王焕灵), Chenyin Jiao(焦陈寅), Jiaze Qin(秦嘉泽), Zejuan Zhang(张泽娟), Shenghai Pei(裴胜海), Suhan Tang(汤苏涵), Feiliang Chen(陈飞良), Ge Tang(汤戈), Juan Xia(夏娟), Chuan Wang(王川), Mo Li(李沫), Hongxia Guo(郭红霞), Xiaoping Ouyang(欧阳晓平), and Jian Zhang(张健)

Chin. Phys. B, 2026, 35 (7): 076104. DOI: 10.1088/1674-1056/ae0d58

Abstract ( 11 )

PDF (22569KB) ( 0 )

The displacement damage (DD) effects induced by low-energy gallium ions (Ga$^{+}$) on single-walled carbon nanotube field-effect transistors (SWCNT FETs) are investigated in this study. Exposure to 5 keV Ga$^{+}$ irradiation resulted in significant changes in the Raman spectra and electrical properties of the devices. The key finding reveals a strong heavy-ion energy dependence of displacement damage (DD): the displacement damage dose ($D_{\rm d}$) induced by 5 keV Ga$^{+}$ irradiation is nearly three orders of magnitude higher than that induced by 2225 MeV xenon ions (Xe$^{+}$). By integrating Raman spectroscopy, electrical characterization, and TRIM simulations, we demonstrate that low-energy heavy ions deposit substantially more energy via non-ionizing energy loss (NIEL) processes within the SWCNT and gate oxide layers compared with high-energy ions. This enhanced energy deposition generates more atomic displacements and vacancies, which significantly degrade both the conductivity of the SWCNT channel and the insulating properties of the gate oxide. These findings provide critical insights into the impact of low-energy ion irradiation on SWCNTs and contribute to a deeper understanding of SWCNT FET behavior in radiation environments.

First-principles prediction of phase transformation and mechanical properties of Mn₂AlB₂ under high pressure

Yi-Xian Wang(王乙先), Zhe Yuan(袁喆), Wu-Na Xie(谢武娜), Yi-Yang Qiu(邱一洋), and Zhao-Qi Wang(王朝棋)

Chin. Phys. B, 2026, 35 (7): 076105. DOI: 10.1088/1674-1056/ae3134

Abstract ( 27 )

PDF (1320KB) ( 5 )

We employ the particle swarm optimization (PSO) algorithm in combination with first-principles calculations to systematically investigate the phase stability and physical properties of Mn$_{2}$AlB$_{2}$ under pressures of up to 80 GPa. The results reveal a pressure-induced phase transition from orthorhombic oC10-Mn$_{2}$AlB$_{2}$ to tetragonal tP10-Mn$_{2}$AlB$_{2}$ at approximately 21.5 GPa, accompanied by a volume collapse of approximately 1.6%, confirming a first-order phase transition. Both phases are mechanically and dynamically stable, with the bulk and shear moduli increasing under compression. The $B$/$G$ ratio and Poisson's ratio indicate a pressure-driven brittle-to-ductile transition occurs at pressures above 50 GPa. The calculated Vickers hardness suggests that the two Mn$_{2}$AlB$_{2}$ phases are potential hard materials rather than superhard ones. Furthermore, the minimum thermal conductivity of both phases exceeds 1.25 W$\cdot$m$^{-1}\cdot$K$^{-1}$, and they are not suitable as thermal barrier coating materials. Electronic structure and bonding analyses reveal that pressure strengthens Mn-B and Al-B bonds and reduces magnetic moments, providing a microscopic explanation for the pressure-dependent mechanical behavior. Finally, a high-pressure and high-temperature phase diagram of Mn$_{2}$AlB$_{2}$ is constructed for the first time using the quasi-harmonic approximation (QHA) method. The results show that the transformation pressure from oC10-Mn$_{2}$AlB$_{2}$ to tP10-Mn$_{2}$AlB$_{2}$ decreases with increasing temperature. These findings deepen our understanding of the pressure-induced behavior of Mn$_{2}$AlB$_{2}$ and provide theoretical guidance for its mechanical optimization and high-pressure synthesis.

Plastic enhancement mechanism of γ-TiAl//α₂-Ti₃Al lamellar structure via Al_Ti antisite defect

Lei Sheng(盛磊), Xiong Zhou(周雄), Qiran Gong(龚琪然), Zhongtao Lu(陆忠涛), Pengcheng Zhai(翟鹏程), Xiege Huang(黄写格), Shiping Wang(王世平), Wenjuan Li(李文娟), Xiaobin Feng(冯骁斌), and Guodong Li(李国栋)

Chin. Phys. B, 2026, 35 (7): 076401. DOI: 10.1088/1674-1056/ae5a10

Abstract ( 6 )

PDF (2444KB) ( 0 )

Polysynthetically twinned (PST) TiAl consisting of a two-phase ($\gamma $ and $\alpha_{2}$) lamellar structure is an effective microstructural strategy for enhancing mechanical properties, and Al-rich composition is a common phenomenon. However, the effect of the Al$_{\rm Ti}$ antisite defect on the deformation mechanism of the $\gamma $-TiAl//$\alpha_{2}$-Ti$_{3}$Al lamellar structure remains unclear. The deformation mechanisms of the $\gamma $//$\alpha_{2}$ lamellar structure under pure shear mainly involve three sequential stages: (i) The weaker Ti-Ti and Al-Al metallic bonds induce the "phase boundary (PB) transition". (ii) The stronger Ti-Ti and Al-Al metallic bonds induce the "orientation transition" in $\gamma $-TiAl. (iii) The strongest Ti-Al covalent bonds induce the "phase transition" in $\alpha_{2}$-Ti$_{3}$Al. Introducing an Al$_{\rm Ti}$ antisite defect can weaken the original Ti-Al covalent bonds while generating new Al-Al metallic bonds, which provides an additional slip path and results in excellent enhancement of plasticity. The competition mechanisms between these plastic behaviors can be well explained through generalized stacking fault energy (GSFE) calculations.

Cascade of low-energy surface phonon modes on the B-terminated EuB₆ surface

Yumeng Li(李雨萌), Meng Li(李萌), Lijing Huang(黄丽静), Haitao Yang(杨海涛), Hongqin Xiao(肖洪钦), Yuxuan He(何昱萱), Geng Li(李更), and Hong-Jun Gao(高鸿钧)

Chin. Phys. B, 2026, 35 (7): 076801. DOI: 10.1088/1674-1056/ae6568

Abstract ( 13 )

PDF (5167KB) ( 5 )

EuB$_{6}$ has emerged as a leading candidate magnetic Weyl semimetal, in which spontaneous ferromagnetic order breaks time-reversal symmetry and drives a topological phase transition accompanied by band inversion. Optical studies have extensively investigated the phonon modes associated with the B$_{6}$ octahedra, whose internal vibrations play an important role in understanding the physical properties of EuB$_{6}$. However, the low-energy phonon modes and their coupling to electrons remain largely unexplored. Here we report a cascade of low-energy phonon modes resolved on the B-terminated surface of EuB$_{6}$ prepared by low-temperature in situ cleavage. We show that defects significantly modulate the local electron-phonon coupling (EPC) strength. Moreover, a defect-pinned $\sqrt {2} \times \sqrt {2} $ short-range order emerges on the B-terminated surface, which selectively modulates the local density of states (LDOS) and the EPC strength. Our results provide insight into the interplay between low-energy surface phonons, defects, and electron-phonon coupling on the B-terminated surface of EuB$_{6}$.

Modulated reconstruction by epitaxial strain engineering and chemical arrangement in SrNbO₃ thin films

Shenggen Cao(曹声根), Jiali Zhao(赵佳丽), Hang Li(李航), and Tian Qian(钱天)

Chin. Phys. B, 2026, 35 (7): 076802. DOI: 10.1088/1674-1056/ae5a0b

Abstract ( 29 )

PDF (1512KB) ( 2 )

Correlated topological quantum materials hold great promise for next-generation quantum technologies, particularly in fault-tolerant quantum computing and energy-efficient spintronic devices, owing to the intricate interplay between strong electron correlations and topologically nontrivial band structures. To experimentally probe correlation-driven band reconstruction, perovskite oxide heterostructures provide an ideal platform, as their epitaxial films offer versatile degrees of freedom for physical modulation through strain or chemical control. In this work, we systematically fabricate high-quality SrNbO₃ thin films via pulsed laser epitaxy and investigate their electronic structures using angle-resolved photoemission spectroscopy (ARPES). Variation of the substrate oxygen stoichiometry drives a transition in the Fermi surface reconstruction from a $\sqrt{2}\!\times\!\sqrt{2}R45^\circ$ pattern on oxygen-deficient SrTiO₃ to a $2\times 2$ pattern on stoichiometric substrates. Furthermore, by precisely controlling the epitaxial thickness, we identify the gradual disappearance of the electron-like Fermi surface at the $M$ point with increasing thickness, which might be associated with the relaxation of the $ a^0a^0c^+ $ lattice distortion induced by interfacial epitaxial strain at the SrTiO₃ substrate. Our findings demonstrate that band reconstruction in correlated oxides can be effectively modulated through chemistry and thin-film thickness, establishing SrNbO₃ as a promising material platform for multifunctional electronic band control. This work provides a prototypical route for exploring the intertwined topological and correlated phenomena in 4d transition-metal oxides under extreme quantum confinement.

Molecular dynamics insights into limited impact of nanoscale defects on lithocholic acid adsorption on graphene

Rui-Jian Yang(杨瑞建) and Zhi-Gang Shao(邵志刚)

Chin. Phys. B, 2026, 35 (7): 076803. DOI: 10.1088/1674-1056/ae504e

Abstract ( 8 )

PDF (2952KB) ( 4 )

Lithocholic acid (LCA), a bile acid metabolite with demonstrated lifespan-extension capabilities, holds considerable biomedical promise. The development of nano-enabled platforms, such as those based on two-dimensional (2D) materials, is crucial to empower its future applications in drug delivery and sensing. For fundamental mechanistic studies, graphene serves as an ideal model system owing to its structural simplicity and computational tractability, which allow for precise control and reliable simulation of its surface properties, such as through defect engineering. However, the adsorption behavior of LCA on graphene surfaces, particularly the mechanistic role of surface defects that are central to tailoring material properties, remains inadequately characterized. To elucidate the underlying physical principles governing this interaction, we employed molecular dynamics simulations to systematically compare LCA binding on ideal graphene (I-Gra) and a series of defective graphene (D-Gra) models with varying defect sizes and edge chemistries. Our results reveal that the binding free energy of LCA converges to a similar value across all surfaces, indicating a limited impact of nanoscale defects. Structural analysis shows that while hydrophilic defect edges form strong, localized hydrogen bonds with water, the overall architecture of the interfacial hydration layer remains largely preserved. This confinement of defect influence leads to minimal variation in the non-polar solvation free energy, the key thermodynamic term governing hydrophobic adsorption. Consequently, the adsorption strength exhibits remarkable robustness against the investigated defects. These findings elucidate a defect-insensitive adsorption mechanism, highlighting that the continuous hydrophobic graphene plane, not localized defect features, dominates the interaction. This insight provides a crucial theoretical foundation for predicting the performance of realistic, non-ideal graphene interfaces in LCA-related biomedical applications.

Pure real energy spectrum and exact anomalous mobility edges in a non-Hermitian flat band geometry

Zhanpeng Lu(陆展鹏), Hui Liu(刘辉), Yan Gu(古燕), and Zhihao Xu(徐志浩)

Chin. Phys. B, 2026, 35 (7): 077101. DOI: 10.1088/1674-1056/ae1efd

Abstract ( 44 )

PDF (2459KB) ( 13 )

The interplay between quasi-periodicity and non-Hermiticity can give rise to rich localization phenomena. In this work, we investigate the localization transition in a one-dimensional nonreciprocal cross-stitch flat band lattice with diagonal quasi-periodic mosaic modulation, which incorporates both constant and quasi-periodic potentials. In general, non-reciprocity induces the skin effect in non-Hermitian systems through nonreciprocal transitions. However, in this work, we find that in a non-reciprocal flat band lattice, when the constant potential is zero, the skin effect does not exist in the system, and the energy spectrum remains purely real and well-defined. In the presence of a non-zero constant potential, we derive analytical solutions for a class of anomalous mobility edges (AMEs) under periodic boundary conditions (PBCs), revealing the systems localization and critical properties. Through analytic results, we demonstrate that the system is fundamentally equivalent to a generalized non-Hermitian Aubry—André (AA) model. Importantly, this equivalence implies the existence of a transition from a critical phase to a localized phase, as predicted by the non-Hermitian AA model. However, our analysis reveals that the transition point from the critical phase to the localized phase is energy-dependent, which fundamentally accounts for the emergence of AMEs. Furthermore, we design a classical electrical circuit to experimentally realize our system. This work provides new insights into localization transitions in non-Hermitian flat band systems.

Structural asymmetry induced high Curie temperature and large out-of-plane piezoelectricity in Gd₂COF MXenes and Gd₂COF/MoS₂ heterostructure

Yan Hu(胡焱), Yu-Ling Song(宋玉玲), Yu-Hong Huang(黄育红), Shu-Yao Cao(曹舒尧), and Fei Ma(马飞)

Chin. Phys. B, 2026, 35 (7): 077102. DOI: 10.1088/1674-1056/ae815f

Abstract ( 8 )

PDF (2029KB) ( 0 )

Two-dimensional (2D) rare-earth (RE) ferromagnetic (FM) materials exhibit significant potential for next-generation spintronic devices. In this work, first-principles calculations are performed to study the MXene Gd$_2$COF monolayer. We demonstrate that Gd$_2$COF is a ferromagnetic half-metal with a large magnetic moment of 13 $\mu_{\rm B}$ per formula unit and a Curie temperature ($T_{\rm C}$) of 750 K, the highest one among the reported RE monolayers. The high $T_{\rm C}$ is attributed to both the out-of-plane structural asymmetry induced interlayer FM double-exchange interaction and the dual intralayer FM super-exchange pathways. Additionally, the system possesses a wide band gap of 3.09 eV and a magnetic anisotropy energy (MAE) of $-0.25 $ meV, features consistent with half-metallicity and ferromagnetism. The monolayer Gd$_2$COF is metallic with $-5 %\sim -4 %$ biaxial strain, transforms into a half-metal with $-3 % \sim 3 %$ biaxial strain, and then becomes a semiconductor with $4 % \sim 5 %$ biaxial strain. It has a high Curie temperature of 550 $\rm K\sim 900 $ K throughout the entire strain range. The Curie temperature decreases with increasing biaxial strain due to the weakened Gd-Gd and Gd-C/O/F bonds. Furthermore, the monolayer exhibits significant out-of-plane piezoelectricity at tensile strains of 4% and 5%. Furthermore, the planar Gd$_2$COF can be stabilized when supported on monolayer MoS$_2$ substrate to avoid bending. The Gd$_{2}$COF/MoS$_{2}$ heterostructure also has a high Curie temperature of 550 $\rm K\sim 900 $ K with $-5 % \sim 5 %$ biaxial strain. The metal-half-metal-semiconductor transition and large piezoelectricity with strain can be similarly observed in this heterostructure.

Proximity-induced negative magnetoresistance and anomalous Hall effect in monolayer graphene/CrSBr heterojunctions

Bin Dai(戴彬), Ke Zhu(祝轲), Chenyu Bai(白晨宇), Yechao Han(韩烨超), Guojing Hu(胡国静), Ruwen Wang(王汝文), Senhao Lv(吕森浩), Haisen Liu(刘海森), Zhen Zhao(赵振), Jianchen Lu(卢建臣), Hui Guo(郭辉), Haitao Yang(杨海涛), and Hong-Jun Gao(高鸿钧)

Chin. Phys. B, 2026, 35 (7): 077201. DOI: 10.1088/1674-1056/ae64d4

Abstract ( 16 )

PDF (657KB) ( 3 )

The integration of graphene with magnetic insulators to invoke the magnetic proximity effect provides a powerful route toward spintronic devices that preserve graphene’s exceptional transport characteristics. A persistent challenge, however, is the identification of magnetic substrates that are both air-stable and capable of forming high-quality van der Waals interfaces. Here, we present a magnetotransport investigation of monolayer graphene coupled to a layered A-type antiferromagnetic semiconductor CrSBr nanoflake, which is notable for its high Néel temperature (~132 K) and outstanding environmental stability. High-quality heterojunctions are obtained via a dry-transfer technique to ensure an atomically clean interface. Pronounced negative magnetoresistance and anomalous Hall effect in graphene are observed, arising from the suppression of spin-disorder scattering induced by the proximity exchange field from the CrSBr layer. Moreover, the heterojunction exhibits clear two-frequency Shubnikov–de Haas oscillations, evidencing the emergence of Fermi surface reconstruction in the monolayer graphene. Our results demonstrate that antiferromagnetic CrSBr can impose a robust magnetic proximity effect that manipulates the spin degrees of freedom in graphene, opening new opportunities for spintronic functionalities in two-dimensional materials.

Spin-bias-controlled current rectification and negative magnetoresistance in a quantum dot spin transistor

Zhengzhong Zhang(张正中), Han Hu(胡涵), Runze Zhu(朱润泽), Yanzong Wang(王延宗), and Hao Liu(刘昊)

Chin. Phys. B, 2026, 35 (7): 077202. DOI: 10.1088/1674-1056/ae1017

Abstract ( 9 )

PDF (1329KB) ( 1 )

We propose a spin-bias-controlled quantum-dot spin-valve device and systematically investigate its charge and spin transport properties. Numerical results reveal that the parallel magnetic configuration enables gate-tunable rectification of both charge and spin currents, whereas no rectification occurs in the antiparallel configuration. Remarkably, in specific gate voltage regimes, the device achieves perfect charge rectification — characterized by complete suppression of reverse-bias charge currents — while sustaining finite spin currents. Furthermore, a negative magnetoresistance emerges in this system, electrically tunable to its theoretical minimum of $-1$, accompanied by an antiparallel to parallel current on/off ratio exceeding $10^{6}$. This behavior implies that within tailored gate voltage regimes, only the antiparallel configuration permits charge conduction, with electron current entirely blocked in the parallel configuration. These results establish spin-bias-driven quantum dot systems as multifunctional platforms for tunable rectification and magnetoresistance control, highlighting their potential for advancing spintronic technologies.

Dehydrogenation-induced polarity flipping of charge carriers and conductance enhancement in nitrogen-containing heterocyclic molecule-anchored single-molecule junctions

Qi Zhou(周琦), Ruimei Liu(刘瑞梅), Guang-Ping Zhang(张广平), Chuan-Kui Wang(王传奎), and Minglang Wang(王明郎)

Chin. Phys. B, 2026, 35 (7): 077301. DOI: 10.1088/1674-1056/ae0d56

Abstract ( 10 )

PDF (1054KB) ( 2 )

Achieving high conductance and dual charge carriers in molecular junctions is essential for developing logical building blocks in molecular electronics. In this study, we investigated the electrical transport properties of nitrogen-containing heterocyclic molecule (N3C)-anchored single-molecule junctions using the nonequilibrium Green's function based on density functional theory. Our findings reveal that dehydrogenation is an effective strategy for achieving two charge-carrier polarities and improving conductance. In particular, dehydrogenation changed the N3C anchor from an electron-rich to an electron-deficient state, reversing the direction of charge transfer and that of the associated interfacial dipole. Consequently, electrons were replaced by holes as the primary charge carriers. Additionally, the number of removed hydrogen atoms critically governs the charge-transport behavior of molecular junctions. When the anchor groups were connected by conjugated molecular bridges, p-type and n-type molecular junctions were produced by removing three and four hydrogen atoms, respectively, significantly increasing junction conductance in both cases. These findings demonstrate that nitrogen-containing heterocyclic molecules are promising anchor groups for achieving two charge-carrier polarities and enhancing conductance through dehydrogenation.

Anisotropic photogalvanic effects in monolayer WSe₂ under elliptically polarized light

Jinyan Niu(牛金艳), Yonghong Ma(马永红), Wuming Liu(刘伍明), and Jia Liu(刘佳)

Chin. Phys. B, 2026, 35 (7): 077302. DOI: 10.1088/1674-1056/ae7a06

Abstract ( 16 )

PDF (866KB) ( 2 )

We investigate the photogalvanic effect in monolayer WSe$_{2}$ under elliptically polarized light using non-equilibrium Green's function density functional theory (NEGF-DFT) simulations. When defects are added that reduce the intrinsic ${D}_{3h}$ symmetry to ${C}_{s}$ and ${C}_{2v}$, the photocurrent shows distinct direction-dependent responses: a sine function of the helicity angle along the zigzag direction and a cosine function along the armchair direction. This anisotropy arises from the specific nonzero tensor elements activated by symmetry reduction. Ga substitution is identified as a highly effective strategy, enhancing the polarization sensitivity by 55.54 times compared to that of pristine WSe$_{2}$. Furthermore, we reveal a resonant enhancement mechanism via impurity states introduced by Ga doping, as confirmed by projected density of states (PDOS) analysis. The application of a small bias voltage (0.04 V) further boosts the photocurrent by up to 368 times. These findings establish a direct link between crystal symmetry, defect engineering, and photoresponse, providing a pathway for high-performance polarization-sensitive optoelectronic devices.

Epitaxial growth of quasi-one-dimensional TaNi₂Se₂ monolayer with anisotropic electronic and mechanical properties

Jiayi Wang(王嘉翌), Qiuchen Yu(余秋辰), Hui Guo(郭辉), Peng Fan(范朋), Siyu Xu(徐思宇), Yixuan Gao(高艺璇), Hui Chen(陈辉), and Hong-Jun Gao(高鸿钧)

Chin. Phys. B, 2026, 35 (7): 077303. DOI: 10.1088/1674-1056/ae5a15

Abstract ( 17 )

PDF (1418KB) ( 3 )

Quasi-one-dimensional (quasi-1D) van der Waals layered materials have garnered significant interest for their intrinsic in-plane anisotropy and potential applications in low-dimensional quantum devices. Here, we report the realization of a quasi-1D TaNi₂Se₂ monolayer with pronounced anisotropic electronic and mechanical properties. The monolayer TaNi₂Se₂ is synthesized on a graphite substrate via van der Waals epitaxy. Using low-temperature scanning tunneling microscopy/spectroscopy, we reveal the characteristic quasi-1D chain-like lattice structure and confirm the intrinsic metallic nature of the monolayer TaNi₂Se₂. Notably, the electronic states exhibit a pronounced quasi-1D modulation that follows the chain structure, indicating strong electronic anisotropy. First-principles calculations further confirm the structural stability and provide signatures of anisotropic in-plane mechanical properties, as well as possible topological edge states arising from spin–orbit coupling. Our findings establish monolayer TaNi₂Se₂ as a novel quasi-1D van der Waals material and provide a promising platform for exploring anisotropy-driven quantum phenomena and device applications.

An efficient and flexible excitation method of gourd-shaped closed-loop high temperature superconducting stacked magnets

Yan-Chen Shi(时雁晨), Yin-Shun Wang(王银顺), Hao-Ran Dong(董浩然), Jun-Hao Liang(梁峻豪), and Yu-Han Liu(刘雨涵)

Chin. Phys. B, 2026, 35 (7): 077401. DOI: 10.1088/1674-1056/ae1de7

Abstract ( 20 )

PDF (1154KB) ( 6 )

Gourd-shaped closed-loop high-temperature superconducting (HTS) stacked magnets are excited by the field cooling (FC) method and can operate in persistent current mode (PCM). While the FC method enables stable PCM operation, its efficiency is limited, and real-time magnetic field adjustment is challenging. According to the law of flux conservation of a superconducting closed loop, an efficient and flexible excitation method is proposed. That is, after the FC excitation process, a reverse current is passed through the excitation coil to generate a reverse magnetic flux, thereby stimulating the magnet to generate a higher magnetic field. Moreover, the magnetic field can be flexibly adjusted by changing the excitation current during the operation of the magnet. Taking the single gourd-shaped HTS plate as the research object, the feasibility of the proposed excitation method is verified through finite element simulations and experiments. The excitation effects of the two methods under the same excitation conditions are compared, and the relationship between magnetic flux density and excitation current is obtained. Results show that the proposed excitation method can stimulate the gourd-shaped HTS magnet to generate a high-intensity magnetic field, and the magnetic field of a single HTS plate is increased by 99.1% compared with that of the FC method under the same excitation conditions. Additionally, the magnetic field intensity can be flexibly adjusted as needed by changing the excitation current during operation.

Current characteristics of strands weaved by transposed REBCO tapes

Heng Zhang(张恒), Jing-Yi Yang(杨敬伊), Zong-Li Wei(魏宗礼), and Wei Pi(皮伟)

Chin. Phys. B, 2026, 35 (7): 077402. DOI: 10.1088/1674-1056/ae181f

Abstract ( 6 )

PDF (1406KB) ( 0 )

A superconducting strand, fabricated by weaving 3, 5, 7, or more transposed rare-earth barium copper oxide (REBCO) high-temperature superconducting (HTS) tapes, is proposed to enhance the critical current and achieve uniform distributions of operating current in each REBCO tape. This design allows all the HTS tapes to quench simultaneously, thereby increasing the critical current compared to a strand simply stacked with HTS tapes and improving HTS tape utilization. Additionally, the transposition strategy can be used to manufacture strands woven with more REBCO tapes for high-current applications such as power transmission. Experimental results demonstrate that strands woven with HTS tapes can enhance the critical current in comparison with strands simply stacked and Roebel cables. Furthermore, a finite element model (FEM) based on the H-formulation has been established to show the operating current distribution.

Superconductivity in monoclinic TiO film

Shihao Liu(刘仕豪), Zongyao Huang(黄宗耀), Huiyu Wang(王慧宇), Wei Hu(胡卫), Xiangyu Hua(华翔宇), Zhaohang Li(李朝航), Zhiwei Wang(王智炜), Feixiong Quan(全飞熊), Zhen Wang(王臻), Jing Tao(陶靖), Tao Wu(吴涛), Xigang Luo(罗习刚), and Xianhui Chen(陈仙辉)

Chin. Phys. B, 2026, 35 (7): 077403. DOI: 10.1088/1674-1056/ae6b3d

Abstract ( 14 )

PDF (2788KB) ( 4 )

Titanium oxide films garner substantial research attention among binary oxides since the superconducting transition temperature of cubic TiO significantly rises from around 2 K in bulk to 7.4 K in thin films. In this study, titanium oxide thin films were fabricated using magnetron sputtering on Al$_2$O$_3$ substrates, where spatially multiphase coexistence was observed. By incorporating a Gd-doped CeO$_{2}$ (GCO) buffer layer, we achieved the epitaxial growth of single-phase monoclinic TiO thin films, which exhibit a superconducting transition temperature of 5 K. Concurrently, a previously unreported superstructure is identified within the GCO intermediate layer, arising from oxygen vacancy ordering during heteroepitaxial growth. These findings confirm the emergence of superconductivity in the monoclinic titanium oxide system and provide valuable insights into elucidating the relationship between the structures and properties of various titanium oxides, as well as the ion redistribution mechanisms during the synthesis of complex oxide thin films.

Review of the strategies for regulating working temperatures of rare-earth-based low temperature magnetic cooling materials

Jie Zhao(赵洁), Yawei Gao(高亚伟), Dingsong Wang(王鼎淞), Shuxian Yang(杨淑娴), Lei Xi(奚磊), Hao Liu(刘昊), Yang Pan(潘洋), Jiawang Xu(许家旺), Xinqi Zheng(郑新奇), and Shouguo Wang(王守国)

Chin. Phys. B, 2026, 35 (7): 077501. DOI: 10.1088/1674-1056/ae3f92

Abstract ( 29 )

PDF (588KB) ( 7 )

Magnetic refrigeration technology based on the magnetocaloric effect (MCE) shows great potential for application in low-temperature fields such as nitrogen, helium, and hydrogen liquefaction. Rare-earth-based compounds usually display outstanding magnetocaloric performance due to the vacant 4f shell and larger magnetic moments, so they have attracted much attention. The working temperature is one of the core parameters of low-temperature magnetic refrigeration materials, which needs to match specific application scenarios ($\sim 4.2$ K for liquid helium, $\sim 20$ K for liquid hydrogen, $\sim 77$ K for liquid nitrogen). This paper reviews the strategies for regulating the working temperatures of rare-earth-based low-temperature magnetic refrigeration materials and concentrates on low-spin rare-earth substitution, zero-spin rare-earth substitution, amorphous engineering, and non-rare-earth atom substitution methods. It provides references for designing low-temperature magnetic refrigeration materials with desired working temperatures.

Heat recycling with magnetocaloric materials for sustainable energy conversion

Fengqi Zhang(张烽起) and Yang Ren(任洋)

Chin. Phys. B, 2026, 35 (7): 077502. DOI: 10.1088/1674-1056/ae3693

Abstract ( 26 )

PDF (1054KB) ( 5 )

Solid-state magnetocaloric effects (MCEs) induced by external magnetic fields offer a promising pathway toward sustainable energy conversion technologies, utilizing field-driven temperature changes for efficient solid-state cooling and heating. This review examines magnetocaloric materials (MCMs) in the context of sustainable heat recycling, summarizing representative material systems and key advances from the past decade. The discussion is organized around a materials—applications—mechanism framework to provide a coherent perspective. Finally, we outline existing challenges and future opportunities in the field. Deeper mechanistic insight, combined with advances in manufacturing and the integration of artificial intelligence and machine learning, is expected to accelerate the development of magnetocaloric energy conversion technologies toward practical implementation. Such synergistic progress will accelerate the deployment of these technologies for carbon-neutral heat recycling.

Review of elastocaloric cooling systems and their performance

Yao Wang(王尧) and Suxin Qian(钱苏昕)

Chin. Phys. B, 2026, 35 (7): 077503. DOI: 10.1088/1674-1056/ae3692

Abstract ( 27 )

PDF (949KB) ( 54 )

Elastocaloric cooling offers a solid-state alternative to conventional vapor-compression systems by leveraging stress-induced phase transitions in materials like shape-memory alloys (SMAs). This review comprehensively analyzes the development and performance of elastocaloric cooling systems to date. We explain the thermodynamic mechanisms and material requirements, emphasizing challenges such as low latent heat and fatigue life. Subsequently, we categorize and compare thermal contact and heat-transfer-fluid (HTF)-based prototypes, discussing their achievements in temperature span and cooling power. The technical maturity of elastocaloric cooling systems is not comparable to that of commercial vapor-compression systems yet in terms of coefficient of performance (COP) and practicality. We further explore innovative approaches like work recovery, modular design, and novel loading modes (e.g., torsion) to bridge application gaps. The review concludes that elastocaloric cooling holds promise for sustainable refrigeration, though material fatigue, system COP, and heat transfer efficiency remain critical bottlenecks for future research.

Recent advances in multiferroics and magnetoelectrics

Zhen Liu(刘振), Jing-Bo Zhou(周靖博), Pin-Yi Zeng(曾品一), Hao-Wen Wang(王好文), and Cheng-Liang Lu(陆成亮)

Chin. Phys. B, 2026, 35 (7): 077504. DOI: 10.1088/1674-1056/ae395c

Abstract ( 33 )

PDF (1060KB) ( 16 )

Multiferroics, where multiple ferroic orders coexist and couple, have been one of the most active fields in condensed matter physics over the past two decades. In particular, the cross-control between magnetic and electric variables, i.e., the magnetoelectric coupling effect, provides a unique advantage for developing low-consumption electronic devices. In recent years, the field has seen a fundamental expansion of its scope to include topological magnetoelectricity and two-dimensional (2D) multiferroics. This review mainly focuses on the progress made in the last decade, covering new material exploration and emerging physical phenomena. It begins with an overview of linear magnetoelectricity, continues with detailed discussions of emerging topological magnetoelectricity and 2D multiferroics, and ends with an outlook on future developments for multiferroicity and magnetoelectric coupling.

Enhanced low-field magnetocaloric effect induced by Co doping in RCu_2-xCo_x (R = Er, Ho) compounds for liquid hydrogen

Lu Tian(田路), Zhaojun Mo(莫兆军), Xuanyu Qiao(乔轩雨), Chenyang Ma(马辰洋), and Guodong Liu(刘国栋)

Chin. Phys. B, 2026, 35 (7): 077505. DOI: 10.1088/1674-1056/ae360a

Abstract ( 6 )

PDF (8169KB) ( 0 )

Hydrogen, as a clean energy carrier, requires liquefaction at 20-77 K, a process that is energy-intensive and traditionally dependent on conventional refrigeration methods. Magnetocaloric refrigeration offers a promising alternative, especially when using permanent magnets as the magnetic field source, which can significantly simplify system design and reduce operational costs. Designing magnetocaloric materials with magnetic ordering temperatures within the hydrogen liquefaction range and exhibiting superior magnetocaloric effects under low magnetic fields is essential for advancing sustainable energy technologies. This study presents an in-depth investigation of the enhanced low-field magnetocaloric effect (MCE) in $R$Cu$_{2-x}$Co$_{x}$ ($R = {\rm rare}$-earth) compounds. The results indicate that Co doping significantly modifies orbital hybridization and magnetic properties, which in turn improves the MCE under low fields. Experimental data confirm that Co-doped compounds show MCE performance at low fields. For instance, under a varying magnetic field of 0-2 T, the volumetric magnetic entropy change of the ErCu$_{1.75}$Co$_{0.25}$ compound reaches 0.12 J$\cdot$cm$^{-3}\cdot$K$^{-1}$. First-principles calculations provide further insights into the electronic density of states and magnetic exchange interactions, clarifying the mechanisms behind the enhanced MCE.

Design of magnetoelectric coupling in ferroelectric metal

Wang Zhang(张旺) and Xue-Zeng Lu(逯学曾)

Chin. Phys. B, 2026, 35 (7): 077506. DOI: 10.1088/1674-1056/ae6173

Abstract ( 31 )

PDF (770KB) ( 3 )

Ferroelectricity and metallicity have traditionally been considered difficult to coexist until the experimental discovery of the polar metal LiOsO$_{3}$ in 2013. Polar metallic materials offer new opportunities for the development of nonvolatile memory. However, simultaneously achieving ferroelectricity, magnetic order, and their strong coupling in a single-phase material remains a challenge. To address this, by using a combination of first-principles calculations and magnetic space group symmetry analysis, we establish a design principle to find magnetoelectric (ME) multiferroics. Our results show that the (CrSb)$_{m}$/(BiSb)$_n$ superlattice with altermagnetic CrSb and ferroelectric BiSb can have ferroelectric and magnetic orders and metallicity. Furthermore, the switching of the polarization can effectively control the weak ferromagnetism in the superlattices, in which the strength of this ME coupling is correlated with the magnitude of the induced polarization in the CrSb layers. Our research provides a material design route for exploring multiferroics with ME coupling.

Prediction of material parameters of spin textures from LTEM images by machine learning models CNN and ViT

Bohan Li(李博涵), Xinyuan Zhang(张歆媛), Guanhua Chen(陈冠桦), and Lin Chen(陈琳)

Chin. Phys. B, 2026, 35 (7): 077507. DOI: 10.1088/1674-1056/ae5db1

Abstract ( 9 )

PDF (1134KB) ( 2 )

Machine learning (ML) models were trained to predict the Dzyaloshinskii-Moriya interaction constant $D$ and anisotropy constant $K$ of spin textures from Lorentz transmission electron microscopy (LTEM) images. Two ML models, convolutional neural network (CNN) and vision transformer (ViT), were trained, tested and employed to predict the values of $D$ and $K$. Firstly, training and testing datasets composed of 9300 topological spin textures were prepared using the micromagnetic simulation method with the values of $D$ and $K$ randomly chosen. Secondly, the performance of the CNN model for predicting $D$ and $K$ values was investigated by varying the number of training data, the pooling process, and the number of fully connected layers, which indicated high prediction accuracies. Thirdly, better performance of the ViT model for predicting $D$ and $K$ values was achieved with the coefficient of determination $R^{2}$ reaching as high as 0.9987 and 0.9991 for predicting $D$ and $K$ values, respectively. Particularly, the reliance on synthetic data and noise robustness was discussed. Finally, the prediction abilities of CNN and ViT models were evaluated and compared. The results of this research indicate that the ML models can achieve the material parameters directly and effectively from LTEM images, and this process may contribute to the design of advanced devices based on the topological spin textures.

Dynamic modes of kπ skyrmions excited by spin waves

Ruiyu Huang(黄瑞玉), Chunjun Qi(祁纯军), Zhe Yi(易哲), Wei Liu(刘巍), Lin Chen(陈琳), and Zhikuo Tao(陶志阔)

Chin. Phys. B, 2026, 35 (7): 077508. DOI: 10.1088/1674-1056/ae118e

Abstract ( 17 )

PDF (739KB) ( 2 )

The dynamic modes of the $k\pi$ skyrmions excited by spin waves are investigated. Firstly, formations of $k\pi$ skyrmions are investigated. Secondly, breathing modes of $k\pi$ skyrmions excited by spin waves are studied, and it is found that spin waves can effectively excite breathing modes. The breathing frequencies excited by spin waves are identical to the intrinsic frequencies for 1$\pi $ skyrmions, while the breathing frequencies excited by spin waves are larger than the intrinsic frequencies for 2$\pi $ skyrmions and 3$\pi $ skyrmions. Thirdly, gyration modes of $k\pi$ skyrmions excited by spin waves are studied, and it is found that spin waves can effectively excite gyration modes. In particular, the ranges of the trajectories driven by spin waves with intrinsic gyration frequencies are larger than the ranges of the trajectories driven by spin waves with other frequencies. This work promotes the understanding of $k\pi$ skyrmion dynamics under spin-wave excitation and provides a platform for developing spin-wave-based microwave devices utilizing $k\pi$ skyrmions.

Regulation of morphology and magnetic properties of ZnFe₂O₄ assemblies via magnetic fields

Xian Zhang(张贤), Jing Meng(孟静), Yeguo Sun(孙业国), Zhe Qu(屈哲), Jun Cao(曹俊), and Yongqing Ma(马永青)

Chin. Phys. B, 2026, 35 (7): 077509. DOI: 10.1088/1674-1056/ae5591

Abstract ( 17 )

PDF (4387KB) ( 3 )

ZnFe$_{2}$O$_{4}$ was synthesized at 200 $^\circ$C via a solvothermal pathway using acetylacetonate salts of zinc and iron as raw materials in self-developed magnetic fields of varying intensities. The following phenomena were observed. During the synthesis process, applying a magnetic field causes spherical assemblies with micrometer-scale diameters to transform into coarse chain-like aggregates exhibiting a length-to-diameter ratio of approximately 4.8. As the strength of the magnetic field increases, the ZnFe$_{2}$O$_{4}$ particle size gradually decreases. The synthetic magnetic field causes the magnetization value of ZnFe$_{2}$O$_{4}$ to increase or decrease. This is due to the interaction between surface spins and bulk spins, and this interaction is regulated by the particle size. The zero-field-cooling (ZFC) curves measured under a 100-Oe (1 Oe = 79.5775 A$\cdot$m$^{-1}$) magnetic field obey the Curie-Weiss law in the high-temperature region. The effective magnetic moments of the superparamagnetic particles obtained through fitting are $\mu_{\rm sp} = 2.53\times10^{4} \mu _{\rm B}$ (ZnFe$_{2}$O$_{4}$ prepared under the condition without magnetic field), $\mu_{\rm sp} = 1.69\times10^{4} \mu_{\rm B}$ (ZnFe$_{2}$O$_{4}$ prepared under the condition of two magnets), and $\mu _{\rm sp} = 1.85\times10^{4} \mu_{\rm B}$ (ZnFe$_{2}$O$_{4}$ prepared under the condition of four magnets). The estimated magnetic particle sizes are 11.4 nm, 10.6 nm, and 9.9 nm, respectively, which are larger than the corresponding sizes (8.6 nm, 7.2 nm, and 6.2 nm) obtained from electron microscopy, indicating that the magnetic moments of adjacent particles tend to be parallel. This work reports a new approach that enables the preparation of magnetic particles with clean surfaces as well as tunable sizes, morphologies, and properties simply by adjusting the magnetic field strength without the need for any additives or templates, thus broadening their potential for various applications.

Higher-order topological semimetal induced by altermagnet

Dengfeng Wang(王登风), Xiang Ji(吉祥), and Sen Cui(崔森)

Chin. Phys. B, 2026, 35 (7): 077510. DOI: 10.1088/1674-1056/ae6b35

Abstract ( 24 )

PDF (3736KB) ( 12 )

Altermagnetism, characterized by momentum-dependent spin splitting in the absence of net magnetization, provides a fertile ground for realizing topological states. Here, we show that coupling a first-order topological insulator to a $d$-wave altermagnet leads to a higher-order topological semimetal phase. This phase simultaneously hosts gap-closing points, robust zero-energy edge states, and corner states. The altermagnetic order parameter governs the motion of the gap-closing points within the Brillouin zone, while the Néel vector determines the spatial localization of the corner states. By mapping out the phase diagram, we identify topological transitions between trivial, higher-order insulating, and higher-order topological semimetal phases. Our findings establish altermagnetic heterostructures as a tunable platform for engineering higher-order topological phases in two dimensions.

Experimental progress on two-dimensional multiferroics

Yuyang Wang(王羽扬), Dacheng Tian(田大铖), and Lan Chen(陈岚)

Chin. Phys. B, 2026, 35 (7): 077511. DOI: 10.1088/1674-1056/ae53b8

Abstract ( 33 )

PDF (955KB) ( 8 )

Two-dimensional (2D) multiferroic materials, characterized by the coexistence of multiple ferroic orders at atomic thicknesses governed by interlayer van der Waals (vdW) interactions, have garnered significant attention due to their exotic physical properties and potential for next-generation information storage, logic, and magnetoelectric spintronic applications, particularly in high-density memory and ultralow-power information processing. This review revisits the fundamental concepts of multiferroicity from symmetry and thermodynamic perspectives, classifies the dominant mechanisms responsible for generating multiferroics and their 2D extensions, and discusses specific material systems ranging from intrinsic to engineered multiferroics. The primary objective of this review is to provide a clear roadmap of the current landscape and offer perspectives on key challenges and opportunities in this rapidly developing field.

Magnetic proximity-induced magnetoresistance in Pt/Tm₃Fe₅O₁₂ heterostructures

Zhengguo Liang(梁正国), Kunjie Dai(戴坤杰), Qiming Lv(吕崎鸣), Ao Wang(王傲), Jinfeng Zhang(章金凤), and Lingfei Wang(王凌飞)

Chin. Phys. B, 2026, 35 (7): 077512. DOI: 10.1088/1674-1056/ae5788

Abstract ( 24 )

PDF (524KB) ( 2 )

Thin Pt films on magnetic garnet exhibit ferromagnetic-like transport properties, which may affect the functionality of Pt in spin current detection, although direct observation of this effect has not been made. Here, we report the observation of a magnetic proximity-induced magnetoresistance (MP-MR) in Pt/Tm$_{3}$Fe$_{5}$O$_{12}$ (TmIG) heterostructures. This electrical signal is directly correlated with the itinerant ferromagnetism induced by the magnetic proximity effect (MPE) at the Pt/TmIG interface. The existence of MP-MR has been unambiguously verified through the insertion of a Cu interlayer and supported by quantitative analysis, which also enables clear differentiation from the spin Hall magnetoresistance (SMR) signal. The weak ferromagnetism observed in Pt follows the typical behavior of itinerant ferromagnetism, as predicted by the Stoner criterion. By utilizing TmIG films with enhanced perpendicular magnetic anisotropy (PMA), we achieve amplification of the MP-MR effect. Our results demonstrate that the magnitude of MP-MR increases with decreasing temperature. Moreover, the strength of MP-MR can be substantially enhanced through improved PMA in TmIG. These findings underscore the potential of MPE-based magnetotransport phenomena for advancing spintronic device applications.

Challenges in piezoelectric force microscopy characterization of sliding ferroelectric WTe₂

Yichen Sun(孙一辰), Luqi Wei(魏鹿奇), Wencheng Fan(范文成), Weihao Sun(孙伟豪), Haonan Wang(王号南), Yaqiong Wang(王亚琼), Zhao Guan(关赵), Wenyi Tong(童文旖), Ke Qu(屈可), Zhenzhong Yang(杨振中), Binbin Chen(陈斌斌), Pinghua Xiang(向平华), Chungang Duan(段纯刚), and Ni Zhong(钟妮)

Chin. Phys. B, 2026, 35 (7): 077701. DOI: 10.1088/1674-1056/ae56e6

Abstract ( 15 )

PDF (1011KB) ( 2 )

Sliding ferroelectricity, an emerging ferroelectric mechanism in 2D systems whose polarization arises from interlayer charge transfer, has attracted considerable attention due to its unique switching behavior, such as superior endurance and high switching speed. However, its experimental characterization remains challenging due to the low polarizability and technical difficulties. Using piezoelectric force microscopy (PFM), we investigate ${\rm T}_{\rm d}$-WTe$_2$ as a model sliding ferroelectric system, aiming to fill the gap in the characterization of sliding ferroelectricity from a microscopic perspective. We observed ferroelectric-like PFM phase contrast and amplitude hysteresis in few-layer (1-4 L) WTe$_{2}$ flakes under ambient conditions, in contrast to the theoretical predictions for flakes thicker than 2 L. Surface oxidation of WTe$_{2}$ has been identified by Raman and other characterization techniques. Therefore, similar PFM characterization has been carried out on the flakes covered by h-BN, which prevented WTe$_{2}$ from oxidation, and no ferroelectric behavior could be found. Consequently, the ferroelectric-like PFM phenomena are attributed to oxidation rather than intrinsic ferroelectricity in WTe$_2$. Combined with analyses of PFM testing principles and the mechanism of sliding ferroelectricity, we identify the limitations and challenges of PFM in characterizing sliding ferroelectricity. This work provides valuable insights for the subsequent characterization and application of related sliding ferroelectrics.

Sliding ferroelectricity and tunable linear and nonlinear optical properties in bilayer SnP₂Se₆

Huicong Li(李汇聪), Yali Yang(杨亚利), Jiangang He(和建刚), and Rongming Wang(王荣明)

Chin. Phys. B, 2026, 35 (7): 077702. DOI: 10.1088/1674-1056/ae8441

Abstract ( 19 )

PDF (2962KB) ( 2 )

Layer stacking of van der Waals bilayers provides an effective means of engineering their physical properties. Here, based on first-principles calculations, we systematically investigate the stacking configurations, electronic structure, and linear and nonlinear optical properties of bilayer SnP$_2$Se$_6$. Our results show that the AB and AC stackings are energetically degenerate polar states connected by interlayer sliding, with a low switching barrier and opposite out-of-plane polarizations. Interlayer sliding markedly modifies the electronic structure and optical response, and reverses the orbital character of the lowest conduction-band states, thereby enabling electric-field control of the spatial distribution of photogenerated electrons and the second-harmonic generation (SHG) response. These findings reveal an intrinsic coupling among stacking patterns, ferroelectric polarization, and nonlinear optical activity, and identify bilayer SnP$_2$Se$_6$ as a promising platform for reconfigurable ferroelectric and optoelectronic devices.

Blue-green luminescence properties and energy transfer in Tm³⁺/Tb³⁺ co-doped TeO₂-GeO₂-Bi₂O₃-BaF₂ glass

Ruizhen Pang(庞瑞祯), Tong Wu(吴童), Kexuan Han(韩科选),Zhenyu Zhou(周振宇), and Wei Zheng(郑威)

Chin. Phys. B, 2026, 35 (7): 077801. DOI: 10.1088/1674-1056/ae12d0

Abstract ( 9 )

PDF (1125KB) ( 0 )

Tm$^{3+}$/Tb$^{3+}$ co-doped TeO$_{2}$-GeO$_{2}$-Bi$_{2}$O$_{3}$-BaF$_{2}$ glasses were synthesized via high-temperature melt-quenching to achieve blue-green fluorescence emission. Under 808-nm pump excitation, the TGBB2 sample (Tm$_{2}$O$_{3}$:Tb$_{4}$O$_{7} = 3:8$) exhibited balanced emissions at 452 nm (blue, Tm$^{3+}$: $^{1}$G$_{4}\to\,{}^{3}$H$_{6}$) and 544 nm (green, Tb$^{3+}$: $^{5}$D$_{4}\to\,{}^{7}$F$_{5}$). With increasing Tb$^{3+}$ concentration, green emission intensity increased while blue emission decreased, confirming efficient Tm$^{3+}\to $Tb$^{3+}$ energy transfer. Key performance metrics for TGBB2 included: a forward energy transfer coefficient of 571.83$\times10^{-40}$ cm$^{6}$/s (far exceeding the reverse coefficient of 63.12$\times10^{-40}$ cm$^{6}$/s), an energy transfer efficiency of 99.5%, maximum emission cross-sections of 5.87$\times10^{-21}$ cm$^{2}$ (476 nm, Tm$^{3+}$) and $3.37\times 10^{-21}$ cm$^{2}$ (486 nm, Tb$^{3+}$), and corresponding gain coefficients of 2.98 cm$^{-1}$ and 0.46 cm$^{-1}$. These results validate the glass's low laser threshold, making Tm$^{3+}$/Tb$^{3+}$ co-doped tellurite-germanate-bismuthate glass a promising candidate for blue-green laser communication and underwater optical transmission.

Non-linear mechanical behavior of amorphous glassy polymers: An experimental review

Peihan Lyu(吕沛函), Zhaoyu Ding(丁肇钰), Jiaxin Hao(郝佳欣), Li Peng(彭莉), Wohua Zhou(周沃华), Xianbo Huang(黄险波), and Xingkun Man(满兴坤)

Chin. Phys. B, 2026, 35 (7): 078101. DOI: 10.1088/1674-1056/ae1e66

Abstract ( 17 )

PDF (1802KB) ( 4 )

This review provides an overview of the non-linear mechanical behavior of amorphous glassy polymers under constant strain rate (CSR) testing. These materials exhibit complex responses to mechanical loading, including yielding, strain softening, and strain hardening, arising from the interplay between their out-of-equilibrium structure and the applied deformation. While many studies have addressed isolated aspects of glassy polymer behavior, a unified examination centered specifically on CSR tests remains limited. We first discuss the fundamental origins of non-linearity, including geometric effects and intrinsic mechanisms. Key features of the mechanical response, such as stress-strain curves, volume changes, molecular mobility, and ductile-brittle behavior, are then described. Finally, the effects of critical experimental variables, including strain rate, temperature, hydrostatic pressure, and thermal history (e.g., aging and annealing), are systematically reviewed. By consolidating findings across diverse studies, this review aims to clarify the characteristic mechanical behavior of amorphous glassy polymers in CSR tests and provide a foundation for future experimental and modeling efforts.

A review from elasto- to twistocaloric cooling

Ziqian Zhang(张子千), Xiang Zhou(周湘), and Zunfeng Liu(刘遵峰)

Chin. Phys. B, 2026, 35 (7): 078102. DOI: 10.1088/1674-1056/ae6174

Abstract ( 22 )

PDF (1792KB) ( 8 )

As a significant branch of solid-state cooling, elastocaloric and twistocaloric cooling achieve reversible temperature changes through the mechanical deformation of functional materials. Compared to vapor-compression refrigeration, they have emerged as promising alternatives because of high efficiency, environmental compatibility, and structural flexibility. Among various cooling strategies, twistocaloric cooling has recently attracted growing attention owing to its large temperature changes under low driving stress through torsional deformation. Here, we summarize recent progress in flexible twistocaloric and elastocaloric materials and devices, covering shape memory alloys, elastomeric polymers, and other emerging polymers. We elucidate the cooling mechanisms from molecular levels and compare the cooling properties among kinds of cooling materials. Then, large- and small-scale cooling devices driven by twisting, uniaxial stretching, and hybrid deformation are clarified, and critical discussions on heat-transfer efficiency, mechanical stability, and scalability are emphasized. Finally, key challenges and future opportunities are outlined from material optimization, device engineering and multi-mode integration, and theoretical modeling perspectives, highlighting pathways toward compact, durable, and energy-efficient solid-state cooling technologies.

Elastocaloric and multicaloric effects in magnetoelastic coupled Ni-Mn-based Heusler shape memory alloys

Yuetong Sun(孙悦彤) and Jian Liu(刘剑)

Chin. Phys. B, 2026, 35 (7): 078103. DOI: 10.1088/1674-1056/ae3607

Abstract ( 28 )

PDF (866KB) ( 9 )

Ni—Mn-based Heusler shape memory alloys (SMAs), considered promising candidates for solid-state refrigeration, possess outstanding elastocaloric effect (eCE) and magnetocaloric effect (MCE) associated with their martensitic transformations (MTs). Driven by stress-induced MTs, the eCE involves the absorption and release of latent heat during the reversible phase transition. Additionally, a strong magnetic response emerges near the MT temperature, giving rise to a multicaloric effect. In this study, the mechanism of magnetoelastic coupling, relevant processing techniques, and multicaloric effects in Ni—Mn-based SMAs are reviewed.

Crossover of rate-limiting processes in mechanochemical reactions under flow driven by applied mechanical stress

Tetsuya Yamamoto, Koji Kubota, Yu Harabuchi, Julong Jiang, and Hajime Ito

Chin. Phys. B, 2026, 35 (7): 078201. DOI: 10.1088/1674-1056/ae5db4

Abstract ( 3 )

PDF (793KB) ( 0 )

Mechanochemical organic synthesis using ball milling leverages mechanical energy to drive chemical reactions. A comprehensive understanding of the underlying reaction kinetics is essential for the continuous development of mechanochemical synthesis. However, the rate-limiting processes of mechanochemical reactions remain poorly understood because molecular behavior at interfacial length scales is still largely unknown. We have theoretically predicted that mechanochemical reactions of two solid reactants lead to the formation of a product-rich phase at their interface due to the instability arising from the immiscibility of product and reactant solids and that the applied mechanical stress accelerates the diffusion of reactants through the product-rich layer by decreasing the thickness of this layer. To shed light on the rate-limiting processes governing such mechanochemical reactions, we develop here a scaling theory. This theory predicts that the rate-limiting process depends on the thickness of the product-rich layer and can therefore change over time. Unlike conventional solution-based reactions, the crossover between regimes of rate-limiting processes is influenced not only by the diffusion length but also by the extent of reactant dissolution into the product-rich layer and the magnitude of the applied mechanical stress. The model developed in this study provides a fundamental framework for a deeper understanding of mechanochemical organic reactions occurring during ball milling.

Tunable Bragg filter based on polymer/silica hybrid waveguide platform

Xinyuan Zhang(张鑫源), Daming Zhang(张大明), Xinjian Zhang(张鑫健), Guoyan Zeng(曾国宴), and Yuexin Yin(尹悦鑫)

Chin. Phys. B, 2026, 35 (7): 078401. DOI: 10.1088/1674-1056/ae0b3b

Abstract ( 15 )

PDF (962KB) ( 4 )

Owing to its compact footprint and superior filter properties, the Bragg grating filter is attractive for applications in optical communications. In this research, we conducted a detailed analysis of the influence of Bragg grating parameters on its functionality and experimentally validated our findings on a simple and low-cost polymer/silica hybrid waveguide platform. The best extinction ratio of 26.3 dB is obtained when the period is 6.63 μm and the number of periods is 200. The full width at half maximum of the grating is 0.35 nm at 1544.74 nm. Tuning efficiency reaches 29.6 pm/mW owing to the high thermo-optical efficiency of the polymer. Finally, we measure the rise and fall times of the grating to be 280 μs. The proposed grating shows great potential in flexible and reconfigurable optical networks.

Enhancing thermoelectric performance in Janus MoTeS through periodic structural alternations and van der Waals contact

Yi-Ming Chen(陈一鸣), Shi-Hua Tan(谭仕华), Xuan-Hao Cao(曹煊浩), and Yan-Hong Zhou(周艳红)

Chin. Phys. B, 2026, 35 (7): 078501. DOI: 10.1088/1674-1056/ae1203

Abstract ( 10 )

PDF (1181KB) ( 3 )

Atomic-scale structural engineering provides a promising approach to enhance the thermoelectric performance of low-dimensional materials. The two-dimensional Janus MoTeS, with its inherent out-of-plane asymmetry, enables direct modulation of thermoelectric transport properties through tailored periodic S-Te atomic arrangements. Herein, three Janus MoTeS configurations with periodic S-Te atom alternation are constructed in order to realize highly efficient thermoelectric properties by first-principles calculations based on density functional theory. The Seebeck coefficient is enhanced and the phonon thermal conductance is suppressed when the alternation frequency of the structure in the transport direction increases, yielding a figure of merit ($ZT$) of 1.58 at 300 K in the high-frequency alternating (HFA) structure. Further, the phonon thermal conductance decreases greatly when the HFA monolayer device is extended into a van der Waals heterojunction, resulting in a high $ZT$ of 1.80 at 300 K, which rises to 3.49 at 500 K. These findings highlight the potential of atomic-level alternation engineering for optimizing thermoelectric performance in Janus 2D materials.

Transmembrane transport of polymer brush-grafted nanoparticles into giant vesicles

Shuai He(贺帅), Junxing Pan(潘俊星), and Jinjun Zhang(张进军)

Chin. Phys. B, 2026, 35 (7): 078701. DOI: 10.1088/1674-1056/ae24ed

Abstract ( 23 )

PDF (656KB) ( 2 )

Polymer brush-grafted nanoparticles have significant application value in fields such as gene therapy and targeted drug delivery. A profound understanding of the interaction mechanisms between these particles and cell membranes represents a critical scientific challenge in biophysics. Using the self-consistent field theory (SCFT), this work systematically explores the transmembrane transport of polymer brush-grafted nanoparticles into giant vesicles. The impacts of critical parameters-polymer brush grafting density, nanoparticle size, and giant vesicle membrane thickness-on transport behavior are comprehensively elucidated. The findings reveal two distinct transmembrane transport mechanisms for polymer brush-grafted nanoparticles, which are governed by membrane thickness and grafting density. At high grafting density, the nanoparticles undergo direct transmembrane translocation; at low grafting density, transport occurs via endocytosis. Thermodynamic analysis identifies entropy as the dominant driving force for this process.

Chaos and complexity in a cardiac pacemaker model with incommensurate fractional-order dynamics: Empirical validation and cardiovascular implications

Haneche Nabil and Hamaizia Tayeb

Chin. Phys. B, 2026, 35 (7): 078702. DOI: 10.1088/1674-1056/ae0b3c

Abstract ( 3 )

PDF (20653KB) ( 1 )

The dynamics of heart rhythms plays a pivotal role in physiological health, where chaotic behavior is often associated with pathological cardiac states. In this work, we investigate a fractional-order model of cardiac pacemaker dynamics using incommensurate derivatives to capture the complex memory effects and non-local interactions inherent in biological systems. We demonstrate that slight variations in the fractional orders induce rich dynamics, including chaos and coexisting attractors, signifying transitions between normal and dysfunctional rhythms. Crucially, our model exhibits wider chaotic regions than classical integer-order counterparts when the incommensurate derivatives are perturbed. Furthermore, we reveal pronounced multistability, where distinct chaotic attractors coexist under identical parameters, reflecting the system's capacity for abrupt transitions between physiological and pathological states. These findings advance the mechanistic understanding of rhythm disorders and highlight the critical role of fractional calculus in modeling cardiac dynamics.

A hypergraph neural network-based framework for identification of Parkinson’s disease subtypes

Meili Lu(卢梅丽) and Hongbao Lu(卢宏保)

Chin. Phys. B, 2026, 35 (7): 078703. DOI: 10.1088/1674-1056/ae2677

Abstract ( 10 )

PDF (1125KB) ( 0 )

Parkinson's disease (PD) exhibits significant phenotypic heterogeneity, which complicates clinical management and underscores the need for precise subtyping. Existing subtyping approaches often rely on a single modality, such as clinical assessments, failing to capture the complex, multi-faceted nature of the disease. This paper proposes a novel computational framework that integrates multi-modal data, specifically preprocessed functional MRI, DNA methylation, and clinical behavioral assessments, for PD subtyping. The methodology involves constructing individual hypergraphs for each modality using $K$-nearest neighbors (KNN), followed by the integration of these hypergraphs into a unified, multi-modal hypergraph using similarity network fusion (SNF). This consolidated hypergraph is then processed via a hypergraph neural network (HGNN) utilizing hyperedge convolution to cluster patients into distinct subtypes. Our experimental results demonstrate that this approach effectively identifies PD subtypes with significant clinical and biological relevance. We provide a comprehensive analysis of the model's performance and further validate the reliability of the identified subtypes through post-hoc statistical tests. This study highlights the potential of graph-based machine learning in disentangling disease heterogeneity, paving the way for personalized therapeutic strategies and improved patient outcomes.

A routing strategy for non-uniform spatial network

Yicong Ye(叶毅聪), Yongxiang Xia(夏永祥), and Haicheng Tu(涂海程)

Chin. Phys. B, 2026, 35 (7): 078901. DOI: 10.1088/1674-1056/ae0a3a

Abstract ( 4 )

PDF (699KB) ( 0 )

As network scales continue to expand, congestion has emerged as a critical issue in the study of complex networks, particularly in spatial networks such as transportation, aviation, and communication systems, where transmission is the primary function. To address this challenge, various routing strategies have been proposed to alleviate congestion by adjusting transmission paths. However, most of these strategies are based on network models that assume a uniform spatial distribution of nodes, which fails to accurately represent the non-uniform distributions observed in real-world networks. In this paper, we construct a more realistic non-uniform spatial network model and propose a novel routing strategy, termed the FH routing strategy, which integrates distance-based degree and harmonic centrality. Simulation results show that the FH strategy effectively avoids high-load nodes, promotes a more balanced load distribution, and significantly improves traffic throughput compared to traditional routing strategies. These findings provide theoretical support and practical guidance for optimizing information transmission in real-world non-uniform spatial networks.

Robustness analysis of binary-coupled logistics-supply chain interdependent networks under load redistribution

Hai-Bo Yu(于海波), Yan-Li Gao(高彦丽), Guang-Ming Chen(陈光明), Qiu-Yu Tang(唐秋宇), Chao Feng(凤超), and Lei Zhang(张雷)

Chin. Phys. B, 2026, 35 (7): 078902. DOI: 10.1088/1674-1056/ae6432

Abstract ( 26 )

PDF (997KB) ( 3 )

To capture the interdependencies between logistics and supply chain networks in real-world systems, this paper develops a load redistribution-based logistics—supply chain binary-coupled network (LSBCN) model. Employing a dynamic load redistribution strategy, we systematically investigate the robustness of the LSBCN under cascading failures. We evaluate network performance under both random and deliberate failures, thoroughly analyze the mechanisms of influence of capacity factor ($\beta$) and capacity index ($\gamma$) on network robustness, and design three optimization strategies: parameter optimization, critical edge protection, and redundant edge addition. Furthermore, we quantitatively examine the synergistic effects and cost-effectiveness among these strategies. The results reveal that capacity factors exert significant regulatory effects on network robustness; however, the marginal improvement diminishes beyond a critical threshold. Distinct optimal capacity parameter configurations correspond to different failure proportions. Protecting critical edges of the logistics network demonstrates superior robustness enhancement under random failures, whereas adding redundant edges proves more effective under deliberate failures. The synergistic effects between strategies exhibit strong dependence on both failure modes and proportions. Under random failures, critical edge protection should be prioritized, while under deliberate failures, redundant edge addition is preferable. These findings provide theoretical foundations and decision-making references for vulnerability assessment, collaborative optimization, and risk management in logistics—supply chain systems.

Impact of resource allocation on information-disease coupled propagation considering node importance in multiplex networks

Liang'an Huo(霍良安), Jiaxue Cha(查佳雪), and Yue Yu(于跃)

Chin. Phys. B, 2026, 35 (7): 078903. DOI: 10.1088/1674-1056/ae31da

Abstract ( 2 )

PDF (1917KB) ( 0 )

During a large-scale epidemic outbreak, effective resource allocation is vital for controlling disease transmission. Prioritizing resource provision to communities experiencing severe infections can mitigate further spread, while prioritizing information dissemination to influential individuals can expand the publicity effect. This paper proposes a novel two-layer information-disease transmission coupled model that optimizes the allocation of information and medical resources based on node importance analysis, aiming to explore the synergistic effects of resource allocation on disease dynamics. The study employs the microscopic Markov chain approach to construct dynamic equations and derive the epidemic threshold, with Monte Carlo simulations used to validate the theoretical results. Findings demonstrate that expanding the scope of preventive information dissemination through mass media improves public awareness of disease prevention and significantly curbs epidemic transmission. Moreover, reducing the resource deployment threshold in infected communities enables more precise resource allocation during the early stages of an outbreak, which is vital for increasing the epidemic threshold and reducing the final size of the epidemic. These findings provide robust theoretical foundations and actionable guidelines for optimizing resource allocation strategies in public health emergency management.

Correlation structure of a complex system from its subsystems’ perspectives

Sen Li(李森), Yan Wang(王燕), Haiying Wang(王海英), Changgui Gu(顾长贵), and Huijie Yang(杨会杰)

Chin. Phys. B, 2026, 35 (7): 078904. DOI: 10.1088/1674-1056/ae42b7

Abstract ( 35 )

PDF (1882KB) ( 7 )

Detecting the correlation between records is a basic task in data science. Today, researchers try to estimate it from an objective perspective; i.e., they try to remain outside the investigated system and adopt a set of measures representing all the agents precisely and completely. This enables them to answer the questions, 'how often', 'how many', or 'what is the relationship between variables'. In reality, the researcher is usually an agent in the investigated system; they themselves design the metrics for the system's state to answer the questions of 'how' and 'why'. In other words, the researcher conducts the investigation from a subjective perspective. Inspired by qualitative research in social science, in this paper we propose a scheme for investigating complex systems from a subjective perspective. Technically, one decomposes the researcher's output time series into intrinsic mode functions that represent their specific features. Projecting all the agents' time series onto the phase space spanned by this set of specific features, one obtains the coordinates of the agents, from which a similarity network is constructed. The properties of this network are then used to produce a portrait of the system's correlation from the researcher's perspective. As typical examples, we investigate three theoretical models, including the Lorenz system, the Rössler system, and their coupled systems. Although Takens's theorem implies that different variables should be equivalent in reconstructing the dynamical behaviors, we find significant differences between them. We also investigate a financial system composed of 22 stock markets, one crude oil market, and one gold market. The similarity networks for markets distributed across the USA, Europe, and China turn out to be largely homogeneous and dominated by star patterns, while those corresponding to markets distributed across Russia, Brazil, India, and South Africa behave inhomogeneously and are dominated by cluster patterns.

Table of contents

Previous issues

1992 - present