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Published in last 1 year |  In last 2 years |  In last 3 years |  All Please wait a minute... For selected: Download citations EndNote Ris BibTeX Toggle thumbnails Select Interparticle-friction-induced anomalous colloid structure Fuzhou Liu(刘福洲), Yu Ding(丁宇), Longfei Li(黎龙飞), Ke Cheng(程可), Fangfu Ye(叶方富), and Mingcheng Yang(杨明成) Chin. Phys. B, 2025, 34 (1): 016401.   DOI: 10.1088/1674-1056/ad9300 Abstract （763）   HTML （290）    PDF （7014KB）（585）       Knowledge map    Interparticle frictional interactions are ubiquitous in colloidal systems, exerting a profound influence on their structural and physical attributes. In this study, we employed Brownian dynamics simulations to explore the non-equilibrium dynamics in colloidal systems, focusing particularly on the role of tangential friction and its influence on the macroscopic physical properties of colloids. We found that the disruption of instantaneous time-reversal symmetry by tangential frictional interactions can trigger the self-assembly of colloidal systems into intricate network configurations, and these novel structures exhibit unique depletion force and rheological properties that set them apart from traditional colloidal gel systems. These findings not only help deepen our comprehension of the self-assembly phenomena in non-equilibrium colloidal systems but also offer fresh insights for the development of colloidal materials with tailored characteristics. Select Electronic structure and carrier mobility of BSb nanotubes Lantian Xue(薛岚天), Chennan Song(宋晨楠), Miaomiao Jian(见苗苗), Qiang Xu(许强), Yuhao Fu(付钰豪), Pengyue Gao(高朋越), and Yu Xie(谢禹) Chin. Phys. B, 2025, 34 (3): 037304.   DOI: 10.1088/1674-1056/adacd3 Abstract （726）   HTML （22）    PDF （1097KB）（724）       Knowledge map    High-mobility semiconductor nanotubes have demonstrated great potential for applications in high-speed transistors, single-charge detection, and memory devices. Here we systematically investigated the electronic properties of single-walled boron antimonide (BSb) nanotubes using first-principles calculations. We observed that rolling the hexagonal boron antimonide monolayer into armchair (ANT) and zigzag (ZNT) nanotubes induces compression and wrinkling effects, significantly modifying the band structures and carrier mobilities through band folding and $\pi^*$-$\sigma^*$ hybridization. As the chiral index increases, the band gap and carrier mobility of ANTs decrease monotonically, where electron mobility consistently exceeds hole mobility. In contrast, ZNTs exhibit a more complex trend: the band gap first increases and then decreases, and the carrier mobility displays oscillatory behavior. In particular, both ANTs and ZNTs could exhibit significantly higher carrier mobilities compared to hexagonal monolayer and zinc-blende BSb, reaching $10^3$-$10^7$ cm$^2\cdot$V$^{-1}\cdot$s$^{-1}$. Our findings highlight strong curvature-induced modifications in the electronic properties of single-walled BSb nanotubes, demonstrating the latter as a promising candidate for high-performance electronic devices. Select Elastic properties of Cu-6wt% Ag alloy wires for pulsed magnets investigated by ultrasonic techniques Ziyu Li(李滋雨), Tianyi Gu(顾天逸), Wenqi Wei(魏文琦), Yang Yuan(袁洋), Zhuo Wang(王卓), Kangjian Luo(罗康健), Yupeng Pan(潘宇鹏), Jianfeng Xie(谢剑峰), Shaozhe Zhang(张绍哲), Tao Peng(彭涛), Lin Liu(柳林), Qi Chen(谌祺), Xiaotao Han(韩小涛), Yongkang Luo(罗永康), and Liang Li(李亮) Chin. Phys. B, 2025, 34 (2): 020701.   DOI: 10.1088/1674-1056/ada1c8 Abstract （677）   HTML （21）    PDF （795KB）（576）       Knowledge map    Conductor materials with good mechanical performance as well as high electrical and thermal conductivities are particularly important to break through the current bottle-neck limit ($\sim 100$ T) of pulsed magnets. Here, we perform systematic studies on the elastic properties of the Cu-6wt% Ag alloy wire, which is a promising candidate material for the new-generation pulsed magnets, by employing two independent ultrasonic techniques, i.e., resonant ultrasound spectroscopy (RUS) and ultrasound pulse-echo experiments. Our RUS measurements manifest that the elastic properties of the Cu-6wt% Ag alloy wires can be improved by an electroplastic drawing procedure as compared with the conventional cold drawing. We also take this opportunity to test the availability of our newly-built ultrasound pulse-echo facility at the Wuhan National High Magnetic Field Center (WHMFC, China), and the results suggest that the elastic performance of the electroplastically-drawn Cu-6wt% Ag alloy wire remains excellent without anomalous softening under extreme conditions, e.g., in ultra-high magnetic field up to 50 T and nitrogen or helium cryogenic liquids. Select Resolving gravitational redshift with sub-millimeter height differences using spin-squeezed optical clocks Deshui Yu(于得水), Jia Zhang(张佳), Shougang Zhang(张首刚), Tiantian Shi(史田田), and Jingbiao Chen(陈景标) Chin. Phys. B, 2025, 34 (5): 054208.   DOI: 10.1088/1674-1056/adca1d Abstract （619）   HTML （13）    PDF （1517KB）（517）       Knowledge map    The phenomenon that a clock at a higher gravitational potential ticks faster than one at a lower potential, also known as gravitational redshift, is one of the classical tests of Einstein's theory of general relativity. Owing to their ultra-high accuracy and stability, state-of-the-art optical lattice clocks have enabled resolving the gravitational redshift with a millimeter-scale height difference. Further reducing the vertical inter-clock separation down to the sub-millimeter level and especially shortening the required measurement time may be achieved by employing spin squeezing. Here, we theoretically investigate the spin-squeezing-enhanced differential frequency comparison between two optical clocks within a lattice-trapped cloud of $^{171}$Yb atoms. The numerical results illustrate that for a sample of $10^{4}$ atoms, the atomic-collision-limited resolution of the vertical separation between two clocks can reach 0.48 mm, corresponding to a fractional gravitational redshift at the $10^{-20}$ level. In addition, the required averaging time may be reduced to less than one hundredth of that of conventional clocks with independent atoms. Our work opens a door to the future spin-squeezing-enhanced test of general relativity. Select Anomalous Hall effect in Bernal tetralayer graphene enhanced by spin-orbit interaction Zhuangzhuang Qu(曲壮壮), Zhihao Chen(陈志豪), Xiangyan Han(韩香岩), Zhiyu Wang(王知雨), Zhuoxian Li(李卓贤), Qianling Liu(刘倩伶), Wenjun Zhao(赵文俊), Kenji Watanabe, Takashi Taniguchi, Zhi-Gang Cheng(程智刚), Zizhao Gan(甘子钊), and Jianming Lu(路建明) Chin. Phys. B, 2025, 34 (3): 037201.   DOI: 10.1088/1674-1056/adb411 Abstract （579）   HTML （29）    PDF （4650KB）（439）       Knowledge map    Spin-orbit interaction (SOI) can be introduced by the proximity effect to modulate the electronic properties of graphene-based heterostructures. In this work, we stack trilayer WSe$_{2}$ on Bernal tetralayer graphene to investigate the influence of SOI on the anomalous Hall effect (AHE). In this structurally asymmetric device, by comparing the magnitude of AHE at positive and negative displacement fields, we find that AHE is strongly enhanced by bringing electrons in proximity to the WSe$_{2}$ layer. Meanwhile, the enhanced AHE signal persists up to 80 K, providing important routes for topological device applications at high temperatures. Select Unveiling the role of high-order anharmonicity in thermal expansion: A first-principles perspective Tianxu Zhang(张天旭), Kun Zhou(周琨), Yingjian Li(李英健), Chenhao Yi(易晨浩), Muhammad Faizan, Yuhao Fu(付钰豪), Xinjiang Wang(王新江), and Lijun Zhang(张立军) Chin. Phys. B, 2025, 34 (4): 046301.   DOI: 10.1088/1674-1056/adb94c Abstract （566）   HTML （2）    PDF （2041KB）（377）       Knowledge map    Thermal expansion is crucial for various industrial processes and is increasingly the focus of research endeavors aimed at improving material performance. However, it is the continuous advancements in first-principles calculations that have enabled researchers to understand the microscopic origins of thermal expansion. In this study, we propose a coefficient of thermal expansion (CTE) calculation scheme based on self-consistent phonon theory, incorporating the fourth-order anharmonicity. We selected four structures (Si, CaZrF$_{6}$, SrTiO$_{3}$, NaBr) to investigate high-order anharmonicity's impact on their CTEs, based on bonding types. The results indicate that our method goes beyond the second-order quasi-harmonic approximation and the third-order perturbation theory, aligning closely with experimental data. Furthermore, we observed that an increase in the ionicity of the structures leads to a more pronounced influence of high-order anharmonicity on CTE, with this effect primarily manifesting in variations of the Grüneisen parameter. Our research provides a theoretical foundation for accurately predicting and regulating the thermal expansion behavior of materials. Select Bayesian phase difference estimation based on single-photon projective measurement Xu-Hao Yu(余旭豪), Ying Wei(韦颖), Ran Yang(杨然), Wen-Hui Song(宋文慧), Yingning Miao(缪应宁), Wei Zhou(周唯), Xinhui Li(李新慧), Xiaoqin Gao(高小钦), Yan-Xiao Gong(龚彦晓), and Shi-Ning Zhu(祝世宁) Chin. Phys. B, 2025, 34 (7): 070305.   DOI: 10.1088/1674-1056/adde33 Abstract （488）   HTML （3）    PDF （1104KB）（398）       Knowledge map    The estimation of quantum phase differences plays an important role in quantum simulation and quantum computation, yet existing quantum phase estimation algorithms face critical limitations in noisy intermediate-scale quantum (NISQ) devices due to their excessive depth and circuit complexity. We demonstrate a high-precision phase difference estimation protocol based on the Bayesian phase difference estimation algorithm and single-photon projective measurement. The iterative framework of the algorithm, combined with the independence from controlled unitary operations, inherently mitigates circuit depth and complexity limitations. Through an experimental realization on the photonic system, we demonstrate high-precision estimation of diverse phase differences, showing root-mean-square errors (RMSE) below the standard quantum limit $\mathcal{O}(1/\sqrt{N})$ and reaching the Heisenberg scaling $\mathcal{O}(1/N)$ after a certain number of iterations. Our scheme provides a critical advantage in quantum resource-constrained scenarios, and advances practical implementations of quantum information tasks under realistic hardware constraints. Select Manipulation of vortex array via a magnetism-tunable spin-polarized scanning tunnelling microscopy Bing Xia(夏冰), Hong-Yuan Chen(陈虹源), Jian Zheng(郑健), Bo Yang(杨波), Jie Cai(蔡杰), Yi Zhang(章毅), Yi Yang(杨毅), Hao Yang(杨浩), Dan-Dan Guan(管丹丹), Xiao-Xue Liu(刘晓雪), Liang Liu(刘亮), Yao-Yi Li(李耀义), Shi-Yong Wang(王世勇), Can-Hua Liu(刘灿华), Hao Zheng(郑浩), and Jin-Feng Jia(贾金锋) Chin. Phys. B, 2025, 34 (3): 037402.   DOI: 10.1088/1674-1056/adb38d Abstract （487）   HTML （17）    PDF （1457KB）（395）       Knowledge map    Manipulating and braiding Majorana zero modes (MZM) are a critical step toward realizing topological quantum computing. The primary challenge is controlling the vortex, which hosts the MZM, within a superconducting film in a spatially precise manner. To address this, we developed a magnetic force-based vortex control technology using the STM system with a self-designed four-electrode piezo-scanner tube and investigated vortex manipulation on the NbSe$_{2}$ superconducting film. We employed ferromagnetic tips to control the movement of vortex array induced by the tip's remanent magnetism. A magnetic core solenoid device was integrated into the STM system and a strong magnetic tip demagnetization technique was developed, providing a viable technical solution for further enabling single vortex manipulation. Select Phase changings in the surface layers of Td-WTe2 driven by alkali-metal deposition Yu Zhu(朱玉), Zheng-Guo Wang(王政国), Yu-Jing Ren(任宇靖), Peng-Hao Yuan(袁鹏浩), Jing-Zhi Chen(陈景芝), Yi Ou(欧仪), Li-Li Meng(孟丽丽), and Yan Zhang(张焱) Chin. Phys. B, 2025, 34 (1): 017302.   DOI: 10.1088/1674-1056/ad9e9e Abstract （474）   HTML （5）    PDF （1825KB）（357）       Knowledge map    The discovery of phase changings in two-dimensional (2D) materials driven by external stimuli not only helps to understand the various intriguing phases in 2D materials but also provides directions for constructing new functional devices. Here, by combining angle-resolved photoemission spectroscopy (ARPES) and in-situ alkali-metal deposition, we studied how alkali-metal adatoms affect the electronic structure of T$_{\rm d}$-WTe$_{2}$ on two different cleaved surfaces. We found that depending on the polarization direction of the cleaved surface, the alkali-metal deposition triggered two successive phase transitions on one surface of WTe$_{2}$, while on the other surface, no phase transition was found. We attributed the observed phase transitions to a T$_{\rm d\uparrow }$-1T$'$-T$_{\rm d\downarrow }$ structural transition driven by an alkali-metal induced sliding of WTe$_{2}$ layers. By comparing the band structure obtained in different structural phases of WTe$_{2}$, we found that the evolution of band structure across different phases is characterized by an energy scale that could be related to the degree of orbital hybridization between two adjacent WTe$_{2}$ layers. Our results demonstrate a method that manipulates the surface structure of bulk 2D materials. It also builds a direct correlation between the electronic structure and the degree of interlayer misalignment in this intriguing 2D material. Select Combining machine learning algorithms with traditional methods for resolving the atomic-scale dynamic structure of monolayer MoS2 in high-resolution transmission electron microscopy Yu Meng(蒙宇), Shuya Wang(王淑雅), Xibiao Ren(任锡标), Han Xue(薛涵), Xuejun Yue(岳学军), Chuanhong Jin(金传洪), Shanggang Lin(林上港), and Fang Lin(林芳) Chin. Phys. B, 2025, 34 (1): 016802.   DOI: 10.1088/1674-1056/ad9ba3 Abstract （471）   HTML （118）    PDF （3615KB）（447）       Knowledge map    High-resolution transmission electron microscopy (HRTEM) promises rapid atomic-scale dynamic structure imaging. Yet, the precision limitations of aberration parameters and the challenge of eliminating aberrations in $Cs$-corrected transmission electron microscopy constrain resolution. A machine learning algorithm is developed to determine the aberration parameters with higher precision from small, lattice-periodic crystal images. The proposed algorithm is then validated with simulated HRTEM images of graphene and applied to the experimental images of a molybdenum disulfide (MoS$_{2}$) monolayer with 25 variables (14 aberrations) resolved in wide ranges. Using these measured parameters, the phases of the exit-wave functions are reconstructed for each image in a focal series of MoS$_{2}$ monolayers. The images were acquired due to the unexpected movement of the specimen holder. Four-dimensional data extraction reveals time-varying atomic structures and ripple. In particular, the atomic evolution of the sulfur-vacancy point and line defects, as well as the edge structure near the amorphous, is visualized as the resolution has been improved from about 1.75 Å to 0.9 Å. This method can help salvage important transmission electron microscope images and is beneficial for the images obtained from electron microscopes with average stability. Select Evolution from the Kondo phase to the RKKY phase in the small impurity spacing regime of the two-impurity Anderson model Hou-Min Du(杜厚旻) and Yu-Liang Liu(刘玉良) Chin. Phys. B, 2025, 34 (2): 027102.   DOI: 10.1088/1674-1056/ada54f Abstract （451）   HTML （9）    PDF （1118KB）（372）       Knowledge map    Understanding the quantum critical phenomena is one of the most important and challenging tasks in condensed matter physics and the two-impurity Anderson model (TIAM) is a good starting point for this exploration. To this end, we employ the algebraic equation of motion approach to calculate the TIAM and analytically obtain the explicit single-particle impurity Green function under the soft cut-off approximation (SCA). This approach effectively incorporates the impurity spacing as an intrinsic parameter. By solving the pole equations of the Green function, we have, for the first time, qualitatively calculated the spectral weight functions of the corresponding low-energy excitations. We find that when the impurity spacing is less than one lattice distance, the dynamic Rudermann-Kittel-Kasuya-Yosida (RKKY) interaction effectively enters, resulting in a rapid increase in the spectral weights of the RKKY phase, which ultimately surpass those of the Kondo phase; while the spectral weights of the Kondo phase are strongly suppressed. From the perspective of spectral weights, we further confirm the existence of a crossover from the Kondo phase to the RKKY phase in the TIAM. Based on these results, the reasons for the phenomenon of the Kondo resonance splitting are also discussed. Select Gate-tunable high-responsivity photodiode based on 2D ambipolar semiconductor Wentao Yu(于文韬), Long Zhao(赵龙), Yanfei Gao(高延飞), Shiping Gao(高石平), Yuekun Yang(杨悦昆), Chen Pan(潘晨), Shi-Jun Liang(梁世军), and Bin Cheng(程斌) Chin. Phys. B, 2025, 34 (1): 018502.   DOI: 10.1088/1674-1056/ad9c44 Abstract （435）   HTML （6）    PDF （1023KB）（260）       Knowledge map    Electrically tunable homojunctions based on ambipolar two-dimensional materials have attracted widespread attention in the field of intelligent vision. These devices exhibit inherent switchable positive and negative photovoltaic properties that effectively mimic the behavior of human retinal cells. However, the photovoltaic responsivity of most electrically tunable homojunctions remains significantly low due to the weak light absorption, making it challenging to meet the application requirements for high-sensitivity target detection in the field of intelligent vision. Here, we propose a gate-tunable photodiode based on two-dimensional ambipolar WSe$_{2}$ with an asymmetric gate electrode, achieving high photovoltaic responsivity. By adjusting the gate voltage and keeping bias voltage zero, we can dynamically realize reconfigurable n$^-$-p and n$^-$-n homojunction states, as well as gate-tunable photovoltaic response characteristics that range from positive to negative. The maximum photovoltaic responsivity of the electrically tunable WSe$_{2}$ homojunction is approximately 0.4 A/W, which is significantly larger than the previously reported value $\sim 0.1 $ A/W in homojunction devices. In addition, the responsivity can be further enhanced to approximately 1.0 A/W when the n$^-$-p photodiode operates in reverse bias mode, enabling high-sensitivity detection of targets. Our work paves the way for developing gate-tunable photodiodes with high photovoltaic responsivity and advancing high-performance intelligent vision technology. Select Stable nanobubbles on ordered water monolayer near ionic model surfaces Luyao Huang(黄璐瑶), Cheng Ling(凌澄), Limin Zhou(周利民), Wenlong Liang(梁文龙), Yujie Huang(黄雨婕), Lijuan Zhang(张立娟), Phornphimon Maitarad, Dengsong Zhang(张登松), and Chunlei Wang(王春雷) Chin. Phys. B, 2025, 34 (1): 014701.   DOI: 10.1088/1674-1056/ad989d Abstract （419）   HTML （6）    PDF （1340KB）（256）       Knowledge map    The stable nanobubbles adhered to mineral surfaces may facilitate their efficient separation via flotation in the mining industry. However, the state of nanobubbles on mineral solid surfaces is still elusive. In this study, molecular dynamics (MD) simulations are employed to examine mineral-like model surfaces with varying degrees of hydrophobicity, modulated by surface charges, to elucidate the adsorption behavior of nanobubbles at the interface. Our findings not only contribute to the fundamental understanding of nanobubbles but also have potential applications in the mining industry. We observed that as the surface charge increases, the contact angle of the nanobubbles increases accordingly with shape transformation from a pancake-like gas film to a cap-like shape, and ultimately forming a stable nanobubble upon an ordered water monolayer. When the solid-water interactions are weak with a small partial charge, the hydrophobic gas (N$_{2}$) molecules accumulate near the solid surfaces. However, we have found, for the first time, that gas molecules assemble a nanobubble on the water monolayer adjacent to the solid surfaces with large partial charges. Such phenomena are attributed to the formation of a hydrophobic water monolayer with a hydrogen bond network structure near the surface. Select Manipulating the magnetic properties of MnBi2Te4 through electrochemical organic molecule intercalation Yu Du(杜钰), Heng Zhang(张恒), Fuwei Zhou(周福伟), Tianqi Wang(王天奇), Jiajun Li(李佳骏), Wuyi Qi(戚无逸), Yiying Zhang (张祎颖), Yefan Yu(俞业凡), Fucong Fei(费付聪), and Fengqi Song(宋凤麒) Chin. Phys. B, 2025, 34 (8): 087302.   DOI: 10.1088/1674-1056/add5cf Abstract （419）   HTML （17）    PDF （1388KB）（417）       Knowledge map    MnBi$_{2}$Te$_{4}$, which is emerging as an intrinsic antiferromagnetic (AFM) topological insulator, provides a unique platform to investigate the interplay between magnetism and topology. Modulating its magnetic properties enables the observation of exotic quantum phenomena such as the quantum anomalous Hall effect, axion insulator states, and Majorana fermions. While the intercalation of Bi$_{2}$Te$_{3}$ can tune its magnetism, synthesizing pure-phase MnBi$_{2}$Te$_{4}$ with uniform Bi$_{2}$Te$_{3}$ intercalation remains challenging, and the fixed interlayer spacing of Bi$_{2}$Te$_{3}$ limits magnetic coupling tunability. Here, we utilize electrochemical organic molecule intercalation to expand the van der Waals gap of MnBi$_{2}$Te$_{4}$ and modulate its magnetic properties. Through x-ray diffraction (XRD) characterizations, we confirm that the interlayer spacing of MnBi$_{2}$Te$_{4}$ is expanded from 13.6 Å to 30.5 Å and 61.0 Å by intercalating quaternary ammonium cations (THA$^{+}$ and CTA$^{+}$), respectively. The THA-MnBi$_{2}$Te$_{4}$ exhibits dual complex magnetic behavior, combining AFM ordering with a Néel temperature ($T_{\rm N}$) of 12 K and a small ferromagnetic hysteresis loop at 2 K. The CTA-MnBi$_{2}$Te$_{4}$ shows robust ferromagnetism, with a Curie point ($T_{\rm C}$) of 15 K, similar to that of the MnBi$_{2}$Te$_{4}$ monolayer. These results demonstrate that remarkable changes in the magnetic properties of MnBi$_{2}$Te$_{4}$ can be achieved via electrochemical intercalation, providing new insights into manipulating magnetism in layered magnetic materials. Select Intensity enhancement of Raman active and forbidden modes induced by naturally occurred hot spot at GaAs edge Tao Liu(刘涛), Miao-Ling Lin(林妙玲), Da Meng(孟达), Xin Cong(从鑫), Qiang Kan(阚强), Jiang-Bin Wu(吴江滨), and Ping-Heng Tan(谭平恒) Chin. Phys. B, 2025, 34 (1): 017801.   DOI: 10.1088/1674-1056/ad9ff9 Abstract （418）   HTML （4）    PDF （5102KB）（274）       Knowledge map    Edge structures are ubiquitous in the processing and fabrication of various optoelectronic devices. Novel physical properties and enhanced light-matter interactions are anticipated to occur at crystal edges due to the broken spatial translational symmetry. However, the intensity of first-order Raman scattering at crystal edges has been rarely explored, although the mechanical stress and edge characteristics have been thoroughly studied by the Raman peak shift and the spectral features of the edge-related Raman modes. Here, by taking GaAs crystal with a well-defined edge as an example, we reveal the intensity enhancement of Raman-active modes and the emergence of Raman-forbidden modes under specific polarization configurations at the edge. This is attributed to the presence of a hot spot at the edge due to the redistributed electromagnetic fields and electromagnetic wave propagations of incident laser and Raman signal near the edge, which are confirmed by the finite-difference time-domain simulations. Spatially-resolved Raman intensities of both Raman-active and Raman-forbidden modes near the edge are calculated based on the redistributed electromagnetic fields, which quantitatively reproduce the corresponding experimental results. These findings offer new insights into the intensity enhancement of Raman scattering at crystal edges and present a new avenue to manipulate light-matter interactions of crystal by manufacturing various types of edges and to characterize the edge structures in photonic and optoelectronic devices. Select Strain-modulated superconductivity of monolayer Tc2B2 Zhengtao Liu(刘正涛), Zihan Zhang(张子涵), Hao Song(宋昊), Tian Cui(崔田), and Defang Duan(段德芳) Chin. Phys. B, 2025, 34 (4): 047104.   DOI: 10.1088/1674-1056/adb94d Abstract （418）   HTML （0）    PDF （5960KB）（331）       Knowledge map    Two-dimensional (2D) superconductors have attracted significant research interest due to their promising potential applications in optoelectronic and microelectronic devices. Herein, we employ first-principles calculations to predicted a new 2D conventional superconductor, Tc$_{2}$B$_{2}$, demonstrating its stable structural configuration. Remarkably, under biaxial strain, the superconducting transition temperature ($T_{\rm c}$) of Tc$_{2}$B$_{2}$ demonstrates a significant enhancement, achieving 19.5 K under 3% compressive strain and 9.2 K under 11% tensile strain. Our study reveals that strain-induced modifications in Fermi surface topology significantly enhance the Fermi surface nesting effect, which amplifies electron-phonon coupling interactions and consequently elevates $T_{\rm c}$. Additionally, the presence of the Lifshitz transition results in a more pronounced rise in $T_{\rm c}$ under compressive strain compared to tensile strain. These insights offer important theoretical guidance for designing 2D superconductors with high-$T_{\rm c}$ through strain modulation. Select All-microwave CZ gate based on fixed-frequency driven coupler Wanpeng Gao(高万鹏), Xiaoliang He(何潇梁), Zhengqi Niu(牛铮琦), Daqiang Bao(包大强), Kuang Liu(刘匡), Junfeng Chen(陈俊锋), Zhen Wang(王镇), and Z. R. Lin(林志荣) Chin. Phys. B, 2025, 34 (4): 040304.   DOI: 10.1088/1674-1056/adb68a Abstract （394）   HTML （1）    PDF （1543KB）（280）       Knowledge map    High-quality entangling gates are crucial for scalable quantum information processing. Implementing all-microwave two-qubit gates on fixed-frequency transmons offers advantages in reducing wiring complexity, but the gate performance is often limited due to the residual $ZZ$ interaction and the frequency crowding problem. Here, we introduce a novel scheme that enables a microwave drive-activated CZ gate compatible with the coupler structure to suppress the residual $ZZ$ interaction. The microwave drive is applied to the coupler and the microwave drive frequency remains far detuned from the system's transition frequency to alleviate the frequency crowding problem. We model the gate process analytically and demonstrate a theoretical gate fidelity up to 99.9% numerically. Our scheme is compatible with current coupler-structure-based circuits, and insensitive to microwave crosstalk, showing a possible path for all-microwave quantum operations at scale. Select Shear viscosity of an ultracold Fermi gas in the BCS-BEC crossover Jing Min(闵靖), Xiangchuan Yan(严祥传), Da-Li Sun(孙大立), Lu Wang(王璐), Xin Xie(谢馨), Xizhi Wu(吴熙至), Shi-Guo Peng(彭世国), and Kaijun Jiang(江开军) Chin. Phys. B, 2025, 34 (5): 053103.   DOI: 10.1088/1674-1056/adc403 Abstract （391）   HTML （10）    PDF （610KB）（369）       Knowledge map    We report on the measurement of shear viscosity in an ultracold Fermi gas with variable temperatures and tunable interactions. A quadrupole mode excitation in an isotropic harmonic trap is used to quantify the shear viscosity of the quantum gas within the hydrodynamic regime. The shear viscosity of the system as a function of temperature has been investigated, and the results closely align with calculations in the high-temperature limit utilizing a new definition of the cutoff radius. Through an adiabatic sweep across the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensate (BEC) crossover, we find that the minimum value of the shear viscosity, as a function of interaction strength, is significantly shifted toward the BEC side. Furthermore, the behavior of the shear viscosity is asymmetric on both sides of the location of the minimum. Select Scaling corrections in driven critical dynamics: Application to the two-dimensional dimerized quantum Heisenberg model Jing-Wen Liu(刘静雯), Shuai Yin(阴帅), and Yu-Rong Shu(舒玉蓉) Chin. Phys. B, 2025, 34 (5): 057502.   DOI: 10.1088/1674-1056/adc672 Abstract （388）   HTML （0）    PDF （799KB）（445）       Knowledge map    Driven critical dynamics in quantum phase transitions holds significant theoretical importance, and also has practical applications in fast-developing quantum devices. While scaling corrections have been shown to play important roles in fully characterizing equilibrium quantum criticality, their impact on nonequilibrium critical dynamics has not been extensively explored. In this work, we investigate the driven critical dynamics in a two-dimensional quantum Heisenberg model. We find that in this model the scaling corrections arising from both finite system size and finite driving rate must be incorporated into the finite-time scaling form in order to properly describe the nonequilibrium scaling behaviors. In addition, improved scaling relations are obtained from the expansion of the full scaling form. We numerically verify these scaling forms and improved scaling relations for different starting states using the nonequilibrium quantum Monte Carlo algorithm. Select Possible coexistence of superconductivity and topological electronic states in 1T-RhSeTe Tengdong Zhang(张腾东), Rui Fan(樊睿), Yan Gao(高炎), Yanling Wu(吴艳玲), Xiaodan Xu(徐晓丹), Dao-Xin Yao(姚道新), and Jun Li(李军) Chin. Phys. B, 2025, 34 (2): 027403.   DOI: 10.1088/1674-1056/ada432 Abstract （377）   HTML （0）    PDF （1824KB）（408）       Knowledge map    Transition metal dichalcogenides (TMDs), exhibit a range of crystal structures and topological quantum states. The 1T phase, in particular, shows promise for superconductivity driven by electron-phonon coupling (EPC), strain, pressure, and chemical doping. In this theoretical investigation, we explore 1T-RhSeTe as a novel type of TMD superconductor with topological electronic states. The optimal doping structure and atomic arrangement of 1T-RhSeTe are constructed. Phonon spectrum calculations validate the integrity of the constructed doping structure. The analysis of the electron-phonon coupling using the electron-phonon Wannier (EPW) method has confirmed the existence of a robust electron-phonon interaction in 1T-RhSeTe, resulting in total EPC constant $\lambda = 2.02$, the logarithmic average frequency $\omega_{\rm log} = 3.15$ meV and $T_{\rm c} = 4.61$ K, consistent with experimental measurements and indicative of its classification as a BCS superconductor. The band structure analysis revealed the presence of Dirac-like band crossing points. The topological non-trivial electronic structures of the 1T-RhSeTe are confirmed via the evolution of Wannier charge centers (WCCs) and time-reversal symmetry-protected topological surface states (TSSs). These distinctive properties underscore 1T-RhSeTe as a possible candidate for a topological superconductor, warranting further investigation into its potential implications and applications. page Page 1 of 4 Total 72 records First page Prev page Next page Last page