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2023年, 第32卷, 第9期　刊出日期：2023-08-15 上一期    下一期

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Design, fabrication and optimization of electromagnetic absorption metamaterials Qi Lou(娄琦), Xu-Dong Zhang(张旭东), and Ming-Gang Xia(夏明岗) 2023 (9):  94102-094102.  doi: 10.1088/1674-1056/accb42 摘要 ( 211 )   HTML ( 8 )   PDF(2240KB) ( 217 )   For decades, the rapid development of wireless communication has provided people a smarter way of living. However, a significant increase in electromagnetic pollution is an unavoidable consequence. Evading radar detection in modern warfare has also become an important prerequisite for survival on the battlefield. This review provides a comprehensive overview of the current status and types of electromagnetic absorption metamaterials, especially their design and preparation methods. Moreover, this review focuses on the strategies used to optimize the absorber absorption performance. Finally, this review presents a viewpoint on future research on electromagnetic absorption metamaterials, the main challenges that need to be addressed and the possible solutions. 参考文献 | 相关文章 | 计量指标

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Crysformer: An attention-based graph neural network for properties prediction of crystals Tian Wang(王田), Jiahui Chen(陈家辉), Jing Teng(滕婧), Jingang Shi(史金钢),Xinhua Zeng(曾新华), and Hichem Snoussi 2023 (9):  90703-090703.  doi: 10.1088/1674-1056/ace247 摘要 ( 225 )   HTML ( 4 )   PDF(591KB) ( 136 )   We present a novel approach for the prediction of crystal material properties that is distinct from the computationally complex and expensive density functional theory (DFT)-based calculations. Instead, we utilize an attention-based graph neural network that yields high-accuracy predictions. Our approach employs two attention mechanisms that allow for message passing on the crystal graphs, which in turn enable the model to selectively attend to pertinent atoms and their local environments, thereby improving performance. We conduct comprehensive experiments to validate our approach, which demonstrates that our method surpasses existing methods in terms of predictive accuracy. Our results suggest that deep learning, particularly attention-based networks, holds significant promise for predicting crystal material properties, with implications for material discovery and the refined intelligent systems. 参考文献 | 相关文章 | 计量指标

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Size effect on transverse free vibrations of ultrafine nanothreads Zhuoqun Zheng(郑卓群), Han Li(李晗), Zhu Su(宿柱), Nan Ding(丁楠), Xu Xu(徐旭),Haifei Zhan(占海飞), and Lifeng Wang(王立峰) 2023 (9):  96202-096202.  doi: 10.1088/1674-1056/ace037 摘要 ( 168 )   HTML ( 2 )   PDF(1679KB) ( 112 )   Due to their unique properties and appealing applications, low dimensional sp3 carbon nanostructures have attracted increasing attention recently. Based on the beam theory and atomistic studies, this work carries out a comprehensive investigation on the vibrational properties of the ultrathin carbon nanothreads (NTH). Size effect is observed in transverse free vibrations of NTHs. To quantify such effects, the modified couple stress theory (MCST) is utilized to modify the Timoshenko beam theory. According to the first four order frequencies of NTHs from atomistic simulations, the critical length scale parameter of MCST is calibrated as 0.1 nm. It is shown that MCST has minor effect on the first four order modal shapes, except for the clamped boundary. MCST makes the modal shapes at the clamped boundary closer to those observed in atomistic simulations. This study suggests that to some extent the MCST-based Timoshenko beam theory can well describe the transverse vibration characteristics of the ultrafine NTHs, which are helpful for designing and fabricating the NTH-based nanoscale mechanical resonators. 参考文献 | 补充材料 | 相关文章 | 计量指标

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Two-dimensional dumbbell silicene as a promising anode material for (Li/Na/K)-ion batteries Man Liu(刘曼), Zishuang Cheng(程子爽), Xiaoming Zhang(张小明), Yefeng Li(李叶枫), Lei Jin(靳蕾),Cong Liu(刘丛), Xuefang Dai(代学芳), Ying Liu(刘影), Xiaotian Wang(王啸天), and Guodong Liu(刘国栋) 2023 (9):  96303-096303.  doi: 10.1088/1674-1056/acd623 摘要 ( 178 )   HTML ( 4 )   PDF(1376KB) ( 151 )   Rechargeable ion batteries require anode materials with excellent performance, presenting a key challenge for researchers. This paper explores the potential of using two-dimensional dumbbell silicene as an anode material for alkali metal ion batteries through density functional theory (DFT) calculations. Our findings demonstrate that alkali metal ions have negative adsorption energies on dumbbell silicene, and the energy barriers for Li/Na/K ion diffusion are as low as 0.032 eV/0.055 eV/0.21 eV, indicating that metal ions can easily diffuse across the entire surface of dumbbell silicene. Additionally, the average open circuit voltages of dumbbell silicene as anode for Li-ion, Na-ion, and K-ion batteries are 0.42 V, 0.41 V, and 0.60 V, respectively, with corresponding storage capacities of 716 mAh/g, 622 mAh/g, and 716 mAh/g. These results suggest that dumbbell silicene is an ideal anode material for Li-ion, Na-ion, and K-ion batteries, with high capacity, low open circuit voltage, and high ion diffusion kinetics. Moreover, our calculations show that the theoretical capacities obtained using DFT-D2 are higher than those obtained using DFT-D3, providing a valuable reference for subsequent theoretical calculations. 参考文献 | 补充材料 | 相关文章 | 计量指标

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Silicon photomultiplier based scintillator thermal neutron detector for China Spallation Neutron Source (CSNS) Xiu-Ping Yue(岳秀萍), Zhi-Fu Zhu(朱志甫), Bin Tang(唐彬), Chang Huang(黄畅), Qian Yu(于潜), Shao-Jia Chen(陈少佳), Xiu-Ku Wang(王修库), Hong Xu(许虹), Shi-Hui Zhou(周诗慧),Xiao-Jie Cai(蔡小杰), Hao Yang(杨浩), Zhi-Yong Wan(万志勇),Zhi-Jia Sun(孙志嘉), and Yun-Tao Liu(刘云涛) 2023 (9):  90402-090402.  doi: 10.1088/1674-1056/ace316 摘要 ( 199 )   HTML ( 5 )   PDF(1677KB) ( 127 )   The energy-resolved neutron imaging spectrometer (ERNI) will be installed in 2022 according to the spectrometer construction plan of the China Spallation Neutron Source (CSNS). The instrument requires neutron detectors with the coverage area of approximately 4 m2 in 5° -170° neutron diffraction angle. The neutron detection efficiency needs to be better than 40% at 1 Å neutron wavelength. The spatial resolution should be better than 3 m mm×50 mm in the horizontal and vertical directions respectively. We develop a one-dimensional scintillator neutron detector which is composed of the 6LiF/ZnS (Ag) scintillation screens, the wavelength-shifting fiber (WLSF) array, the silicon photomultipliers (SiPMs), and the self-designed application-specific integrated circuit (ASIC) readout electronics. The pixel size of the detector is designed as 3 m mm×50 mm, and the neutron-sensitive area is 50 m mm×200 mm. The performance of the detector prototype is measured using neutron beam 20# of the CSNS. The maximum counting rate of 247 kHz, and the detection efficiency of 63% at 1.59 Å are obtained. The test results show that the performance of the detector fulfills the physical requirements of the ERNI under construction at the CSNS. 参考文献 | 相关文章 | 计量指标

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FPGA based hardware platform for trapped-ion-based multi-level quantum systems Ming-Dong Zhu(朱明东), Lin Yan(闫林), Xi Qin(秦熙),Wen-Zhe Zhang(张闻哲), Yiheng Lin(林毅恒), and Jiangfeng Du(杜江峰) 2023 (9):  90702-090702.  doi: 10.1088/1674-1056/accb48 摘要 ( 160 )   HTML ( 7 )   PDF(2819KB) ( 125 )   We report a design and implementation of a field-programmable-gate-arrays (FPGA) based hardware platform, which is used to realize control and signal readout of trapped-ion-based multi-level quantum systems. This platform integrates a four-channel 2.8 Gsps@14 bits arbitrary waveform generator, a 16-channel 1 Gsps@14 bits direct-digital-synthesis-based radio-frequency generator, a 16-channel 8 ns resolution pulse generator, a 10-channel 16 bits digital-to-analog-converter module, and a 2-channel proportion integration differentiation controller. The hardware platform can be applied in the trapped-ion-based multi-level quantum systems, enabling quantum control of multi-level quantum system and high-dimensional quantum simulation. The platform is scalable and more channels for control and signal readout can be implemented by utilizing more parallel duplications of the hardware. The hardware platform also has a bright future to be applied in scaled trapped-ion-based quantum systems. 参考文献 | 相关文章 | 计量指标

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Anti-Stokes/Stokes temperature calibration and its application in laser-heating diamond anvil cells Minmin Zhao(赵旻旻), Binbin Wu(吴彬彬), Jingyi Liu(刘静仪), and Li Lei(雷力) 2023 (9):  90704-090704.  doi: 10.1088/1674-1056/accd55 摘要 ( 201 )   HTML ( 3 )   PDF(1217KB) ( 112 )   Anti-Stokes/Stokes Raman peak intensity ratio was used to infer sample temperatures, but the influence factors of system correction factors were not clear. Non-contact in-situ anti-Stokes/Stokes temperature calibration was carried out for up to 1500 K based on six different samples under two excitation light sources (±50 K within 1000 K, ±100 K above 1000 K), and the system correction factor γ was systematically investigated. The results show that the correction factor γ of anti-Stokes/Stokes thermometry is affected by the wavelength of the excitation light source, Raman mode peak position, temperature measurement region and other factors. The anti-Stokes/Stokes thermometry was applied to the laser-heating diamond anvil cell (LHDAC) experiment to investigate the anharmonic effect of hBN under high temperature and high pressure. It is concluded that the strong anharmonic effect caused by phonon scattering at low pressure gradually changes into the predominance of localized molecular lattice thermal expansion at high pressure. 参考文献 | 相关文章 | 计量指标

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An injection-locking diode laser at 671 nm with a wide tuning range up to 6 GHz Hong-Fang Song(宋红芳), Yue Shen(沈玥), and Ke Li(李可) 2023 (9):  94205-094205.  doi: 10.1088/1674-1056/acd62a 摘要 ( 170 )   HTML ( 2 )   PDF(1168KB) ( 109 )   We present a compact injection-locking diode laser module to generate 671 nm laser light with a high output power up to 150 mW. The module adopts a master-slave injection-locking scheme, and the injection-locking state is monitored using the transmission spectrum from a Fabry-Pérot interferometer. Beat frequency spectrum measurement shows that the injection-locked slave laser has no other frequency components within the 150-MHz detection bandwidth. It is found that without additional electronic feedback, the slave laser can follow the master laser over a wide range of 6 GHz. All the elements of the module are commercially available, which favors fast construction of a complete 671-nm laser system for the preparation of cold 6Li atoms with only one research-grade diode laser as the seeding source. 参考文献 | 相关文章 | 计量指标

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Elemental composition x-ray fluorescence analysis with a TES-based high-resolution x-ray spectrometer Bingjun Wu(吴秉骏), Jingkai Xia(夏经铠), Shuo Zhang(张硕), Qiang Fu(傅强), Hui Zhang(章辉),Xiaoming Xie(谢晓明), and Zhi Liu(刘志) 2023 (9):  97801-097801.  doi: 10.1088/1674-1056/acd926 摘要 ( 175 )   HTML ( 3 )   PDF(5475KB) ( 354 )   The accurate analysis of the elemental composition plays a crucial role in the research of functional materials. The emitting characteristic x-ray fluorescence (XRF) photons can be used for precisely discriminating the specified element. The detection accuracy of conventional XRF methodology using semiconductor detector is limited by the energy resolution, thus posing a challenge in accurately scaling the actual energy of each XRF photon. We adopt a novel high-resolution x-ray spectrometer based on the superconducting transition-edge sensor (TES) for the XRF spectroscopy measurement of different elements. Properties including high energy resolution, high detection efficiency and precise linearity of the new spectrometer will bring significant benefits in analyzing elemental composition via XRF. In this paper, we study the emph{L}-edge emission line profiles of three adjacent rare earth elements with the evenly mixed sample of their oxide components: terbium, dysprosium and holmium. Two orders of magnitude better energy resolution are obtained compared to a commercial silicon drift detector. With this TES-based spectrometer, the spectral lines overlapped or interfered by background can be clearly distinguished, thus making the chemical component analysis more accurate and quantitative. A database of coefficient values for the line strength of the spectrum can then be constructed thereafter. Equipped with the novel XRF spectrometer and an established coefficient database, a direct analysis of the composition proportion of a certain element in an unknown sample can be achieved with high accuracy. 参考文献 | 相关文章 | 计量指标

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Emergence of correlations in twisted monolayer-trilayer graphene heterostructures Zhang Zhou(周璋), Kenji Watanabe, Takashi Taniguchi, Xiao Lin(林晓), Jinhai Mao(毛金海), and Hong-Jun Gao(高鸿钧) 2023 (9):  97203-097203.  doi: 10.1088/1674-1056/ace3a8 摘要 ( 474 )   HTML ( 23 )   PDF(1897KB) ( 494 )   Twisted bilayer graphene heterostructures have recently emerged as a well-established platform for studying strongly correlated phases, such as correlated insulating, superconducting, and topological states. Extending this notion to twisted multilayer graphene heterostructures has exhibited more diverse correlated phases, as some fundamental properties related to symmetry and band structures are correspondingly modified. Here, we report the observations of correlated states in twisted monolayer-trilayer (Bernal stacked) graphene heterostructures. Correlated phases at integer fillings of the moiré unit cell are revealed at a high displacement field and stabilized with a moderate magnetic field on the electron-doping side at a twist angle of 1.45°, where the lift of degeneracy at the integer fillings is observed in the Landau fan diagram. Our results demonstrate the effectiveness of moiré engineering in an extended structure and provide insights into electric-field tunable correlated phases. 参考文献 | 补充材料 | 相关文章 | 计量指标

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General mapping of one-dimensional non-Hermitian mosaic models to non-mosaic counterparts: Mobility edges and Lyapunov exponents Sheng-Lian Jiang(蒋盛莲), Yanxia Liu(刘彦霞), and Li-Jun Lang(郎利君) 2023 (9):  97204-097204.  doi: 10.1088/1674-1056/ace426 摘要 ( 313 )   HTML ( 9 )   PDF(2083KB) ( 422 )   We establish a general mapping from one-dimensional non-Hermitian mosaic models to their non-mosaic counterparts. This mapping can give rise to mobility edges and even Lyapunov exponents in the mosaic models if critical points of localization or Lyapunov exponents of localized states in the corresponding non-mosaic models have already been analytically solved. To demonstrate the validity of this mapping, we apply it to two non-Hermitian localization models: an Aubry-André-like model with nonreciprocal hopping and complex quasiperiodic potentials, and the Ganeshan-Pixley-Das Sarma model with nonreciprocal hopping. We successfully obtain the mobility edges and Lyapunov exponents in their mosaic models. This general mapping may catalyze further studies on mobility edges, Lyapunov exponents, and other significant quantities pertaining to localization in non-Hermitian mosaic models. 参考文献 | 相关文章 | 计量指标

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Phase transition in bilayer quantum Hall system with opposite magnetic field Ke Yang(杨珂) 2023 (9):  97303-097303.  doi: 10.1088/1674-1056/ace61d 摘要 ( 245 )   HTML ( 6 )   PDF(1303KB) ( 200 )   We construct a mapped bilayer quantum Hall system to realize the proposal that two nearly flatbands have opposite Chern numbers. For the C=±1 case, the two Landau levels of the bilayer experience opposite magnetic fields. We consider a mapped bilayer quantum Hall system at total filling νt=1/2+1/2 where the intralayer interaction is repulsive and the interlayer interaction is attractive. We take exact diagonalization (ED) calculations on a torus to study the phase transition when the separation distance d/lB is driven. The critical point at dc/lB = 0.68 is characterized by a collapse of degeneracy and a crossing of energy levels. In the region d/lB<dc/lB, the states of each level are highly degenerate. The pair-correlation function indicates electrons with opposite pseudo-spins are strong correlated at r=0. We find an exciton stripe phase composed of bound pairs. The ferromagnetic ground state is destroyed by the strong effective attractive potential. An electron composite-Fermion (eCF) and a hole composite Fermion (hCF) are tightly bound. In the region d/lB>dc/lB, a crossover from the d→dc limit to the large d limit is observed. The electron and hole composite Fermion liquids (CFL) are realized by composite Fermions (CF) which attach opposite fluxes, respectively. 参考文献 | 相关文章 | 计量指标

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Novel double channel reverse conducting GaN HEMT with an integrated MOS-channel diode Xintong Xie(谢欣桐), Cheng Zhang(张成), Zhijia Zhao(赵智家), Jie Wei(魏杰),Xiaorong Luo(罗小蓉), and Bo Zhang(张波) 2023 (9):  98506-098506.  doi: 10.1088/1674-1056/ace248 摘要 ( 196 )   HTML ( 0 )   PDF(1360KB) ( 221 )   A novel normally-off double channel reverse conducting (DCRC) HEMT with an integrated MOS-channel diode (MCD) is proposed and investigated by TCAD simulation. The proposed structure has two features: one is double heterojunctions to form dual 2DEG channels named the 1st path and the 2nd path for reverse conduction, and the other is the MCD forming by the trench source metal, source dielectric, and GaN. At the initial reverse conduction stage, the MCD acts as a switch to control the 1st path which would be turned on prior to the 2nd path. Because of the introduction of the 1st path, the DCRC-HEMT has an additional reverse conducting channel to help enhance the reverse conduction performance. Compared with the conventional HEMT (Conv. HEMT), the DCRC-HEMT can obtain a low reverse turn-on voltage (VRT) and its VRT is independent of the gate-source bias (VGS) at the same time. The DCRC-HEMT achieves the VRT of 0.62 V, which is 59.7% and 75.9% lower than that of the Conv. HEMT at VGS = 0 V and -1 V, respectively. In addition, the forward conduction capability and blocking characteristics almost remain unchanged. In the end, the key fabrication flows of DCRC-HEMT are presented. 参考文献 | 相关文章 | 计量指标

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Planar InAlAs/InGaAs avalanche photodiode with 360 GHz gain×bandwidth product Shuai Wang(王帅), Han Ye(叶焓), Li-Yan Geng(耿立妍), Fan Xiao(肖帆), Yi-Miao Chu(褚艺渺), Yu Zheng(郑煜), and Qin Han(韩勤) 2023 (9):  98507-098507.  doi: 10.1088/1674-1056/ace61b 摘要 ( 220 )   HTML ( 5 )   PDF(1768KB) ( 215 )   This paper describes a guardring-free planar InAlAs/InGaAs avalanche photodiode (APD) by computational simulations and experimental results. The APD adopts the structure of separate absorption, charge, and multiplication (SACM) with top-illuminated. Computational simulations demonstrate how edge breakdown effect is suppressed in the guardring-free structure. The fabricated APD experiment results show that it can obtain a very low dark current while achieving a high gain×bandwidth (GB) product. The dark current is 3 nA at 0.9Vbr, and the unit responsivity is 0.4 A/W. The maximum 3 dB bandwidth of 24 GHz and a GB product of 360 GHz are achieved for the fabricated APD operating at 1.55 upmu m. 参考文献 | 相关文章 | 计量指标

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Dynamic responses of an energy harvesting system based on piezoelectric and electromagnetic mechanisms under colored noise Yong-Ge Yang(杨勇歌), Yun Meng(孟运), Yuan-Hui Zeng(曾远辉), and Ya-Hui Sun(孙亚辉) 2023 (9):  90201-090201.  doi: 10.1088/1674-1056/acd621 摘要 ( 198 )   HTML ( 0 )   PDF(2337KB) ( 129 )   Because of the increasing demand for electrical energy, vibration energy harvesters (VEHs) that convert vibratory energy into electrical energy are a promising technology. In order to improve the efficiency of harvesting energy from environmental vibration, here we investigate a hybrid VEH. Unlike previous studies, this article analyzes the stochastic responses of the hybrid piezoelectric and electromagnetic energy harvesting system with viscoelastic material under narrow-band (colored) noise. Firstly, a mass-spring-damping system model coupled with piezoelectric and electromagnetic circuits under fundamental acceleration excitation is established, and analytical solutions to the dimensionless equations are derived. Then, the formula of the amplitude-frequency responses in the deterministic case and the first-order and second-order steady-state moments of the amplitude in the stochastic case are obtained by using the multi-scales method. The amplitude-frequency analytical solutions are in good agreement with the numerical solutions obtained by the Monte Carlo method. Furthermore, the stochastic bifurcation diagram is plotted for the first-order steady-state moment of the amplitude with respect to the detuning frequency and viscoelastic parameter. Eventually, the influence of system parameters on mean-square electric voltage, mean-square electric current and mean output power is discussed. Results show that the electromechanical coupling coefficients, random excitation and viscoelastic parameter have a positive effect on the output power of the system. 参考文献 | 相关文章 | 计量指标

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Intervention against information diffusion in static and temporal coupling networks Yun Chai(柴允), You-Guo Wang(王友国), Jun Yan(颜俊), and Xian-Li Sun(孙先莉) 2023 (9):  90202-090202.  doi: 10.1088/1674-1056/acb9f4 摘要 ( 160 )   HTML ( 0 )   PDF(2135KB) ( 51 )   Information diffusion in complex networks has become quite an active research topic. As an important part of this field, intervention against information diffusion processes is attracting ever-increasing attention from network and control engineers. In particular, it is urgent to design intervention schemes for the coevolutionary dynamics between information diffusion processes and coupled networks. For this purpose, we comprehensively study the problem of information diffusion intervention over static and temporal coupling networks. First, individual interactions are described by a modified activity-driven network (ADN) model. Then, we establish a novel node-based susceptible-infected-recovered-susceptible (SIRS) model to characterize the information diffusion dynamics. On these bases, three synergetic intervention strategies are formulated. Second, we derive the critical threshold of the controlled-SIRS system via stability analysis. Accordingly, we exploit a spectral optimization scheme to minimize the outbreak risk or the required budget. Third, we develop an optimal control scheme of dynamically allocating resources to minimize both system loss and intervention expense, in which the optimal intervention inputs are obtained through optimal control theory and a forward-backward sweep algorithm. Finally, extensive simulation results validate the accuracy of theoretical derivation and the performance of our proposed intervention schemes. 参考文献 | 相关文章 | 计量指标

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Turing pattern selection for a plant-wrack model with cross-diffusion Ying Sun(孙颖), Jinliang Wang(王进良), You Li(李由), Nan Jiang(江南), and Juandi Xia(夏娟迪) 2023 (9):  90203-090203.  doi: 10.1088/1674-1056/acac13 摘要 ( 168 )   HTML ( 0 )   PDF(1976KB) ( 135 )   We investigate the Turing instability and pattern formation mechanism of a plant-wrack model with both self-diffusion and cross-diffusion terms. We first study the effect of self-diffusion on the stability of equilibrium. We then derive the conditions for the occurrence of the Turing patterns induced by cross-diffusion based on self-diffusion stability. Next, we analyze the pattern selection by using the amplitude equation and obtain the exact parameter ranges of different types of patterns, including stripe patterns, hexagonal patterns and mixed states. Finally, numerical simulations confirm the theoretical results. 参考文献 | 相关文章 | 计量指标

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Quantum correlation enhanced bound of the information exclusion principle Jun Zhang(张钧), Kan He(贺衎), Hao Zhang(张昊), and Chang-Shui Yu(于长水) 2023 (9):  90301-090301.  doi: 10.1088/1674-1056/accf80 摘要 ( 163 )   HTML ( 0 )   PDF(910KB) ( 96 )   We investigate the information exclusion principle for multiple measurements with assistance of multiple quantum memories that are well bounded by the upper and lower bounds. The lower bound depends on the observables' complementarity and the complementarity of uncertainty whilst the upper bound includes the complementarity of the observables, quantum discord, and quantum condition entropy. In quantum measurement processing, there exists a relationship between the complementarity of uncertainty and the complementarity of information. In addition, based on the information exclusion principle the complementarity of uncertainty and the shareability of quantum discord can exist as an essential factor to enhance the bounds of each other in the presence of quantum memory. 参考文献 | 相关文章 | 计量指标

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Floquet dynamical quantum phase transitions in transverse XY spin chains under periodic kickings Li-Na Luan(栾丽娜), Mei-Yu Zhang(张镁玉), and Lin-Cheng Wang(王林成) 2023 (9):  90302-090302.  doi: 10.1088/1674-1056/accf68 摘要 ( 142 )   HTML ( 0 )   PDF(4950KB) ( 72 )   Floquet dynamical quantum phase transitions (DQPTs), which are nonanalytic phenomena recuring periodically in time-periodic driven quantum many-body systems, have been widely studied in recent years. In this article, the Floquet DQPTs in transverse XY spin chains under the modulation of δ-function periodic kickings are investigated. We analytically solve the system, and by considering the eigenstate as well as the ground state as the initial state of the Floquet dynamics, we study the corresponding multiple Floquet DQPTs emerged in the micromotion with different kicking moments. The rate function of return amplitude, the Pancharatnam geometric phase and the dynamical topological order parameter are calculated, which consistently verify the emergence of Floquet DQPTs in the system. 参考文献 | 相关文章 | 计量指标

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Generalized uncertainty principle from long-range kernel effects: The case of the Hawking black hole temperature Rami Ahmad El-Nabulsi and Waranont Anukool 2023 (9):  90303-090303.  doi: 10.1088/1674-1056/acac15 摘要 ( 157 )   HTML ( 0 )   PDF(703KB) ( 132 )   We prove the existence of an analogy between spatial long-range interactions, which are of the convolution-type introduced in non-relativistic quantum mechanics, and the generalized uncertainty principle predicted from quantum gravity theories. As an illustration, black hole temperature effects are discussed. It is observed that for specific choices of the moment's kernels, cold black holes may emerge in the theory. 参考文献 | 相关文章 | 计量指标

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Commensurate and incommensurate Haldane phases for a spin-1 bilinear-biquadratic model Yan-Wei Dai(代艳伟), Ai-Min Chen(陈爱民), Xi-Jing Liu(刘希婧), and Yao-Heng Su(苏耀恒) 2023 (9):  90304-090304.  doi: 10.1088/1674-1056/acac0c 摘要 ( 170 )   HTML ( 0 )   PDF(1098KB) ( 34 )   Commensurate and incommensurate Haldane phases for a spin-1 bilinear-biquadratic model are investigated using an infinite matrix product state algorithm. The bipartite entanglement entropy can detect a transition point between the two phases. In both phases, the entanglement spectrum shows double degeneracy. We calculate the nonlocal order parameter of the bond-centered inversion in both phases, which rapidly approaches a saturation value of -1 as the segment length increases. The nonlocal order parameter of the bond-centered inversion with a saturation value -1 and the nonzero value string order indicate that the Haldane phase is a symmetry-protected topological phase. To distinguish the commensurate and incommensurate Haldane phases, the transversal spin correlation and corresponding momentum distribution of the structure factor are analyzed. As a result, the transversal spin correlations exhibit different decay forms in both phases. 参考文献 | 相关文章 | 计量指标

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Nonlinear modes coupling of trapped spin-orbit coupled spin-1 Bose-Einstein condensates Jie Wang(王杰), Jun-Cheng Liang(梁俊成), Zi-Fa Yu(鱼自发), An-Qing Zhang(张安庆),Ai-Xia Zhang(张爱霞), and Ju-Kui Xue(薛具奎) 2023 (9):  90305-090305.  doi: 10.1088/1674-1056/accd53 摘要 ( 210 )   HTML ( 3 )   PDF(1147KB) ( 78 )   We study analytically and numerically the nonlinear collective dynamics of quasi-one-dimensional spin-orbit coupled spin-1 Bose-Einstein condensates trapped in harmonic potential. The ground state of the system is determined by minimizing the Lagrange density, and the coupled equations of motions for the center-of-mass coordinate of the condensate and its width are derived. Then, two low energy excitation modes in breathing dynamics and dipole dynamics are obtained analytically, and the mechanism of exciting the anharmonic collective dynamics is revealed explicitly. The coupling among spin-orbit coupling, Raman coupling and spin-dependent interaction results in multiple external collective modes, which leads to the anharmonic collective dynamics. The cooperative effect of spin momentum locking and spin-dependent interaction results in coupling of dipolar and breathing dynamics, which strongly depends on spin-dependent interaction and behaves distinct characters in different phases. Interestingly, in the absence of spin-dependent interaction, the breathing dynamics is decoupled from spin dynamics and the breathing dynamics is harmonic. Our results provide theoretical evidence for deep understanding of the ground sate phase transition and the nonlinear collective dynamics of the system. 参考文献 | 相关文章 | 计量指标

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Generation of hyperentangled photon pairs based on lithium niobate waveguide Yang-He Chen(陈洋河), Zhen Jiang(姜震), and Guang-Qiang He(何广强) 2023 (9):  90306-090306.  doi: 10.1088/1674-1056/acd5c4 摘要 ( 165 )   HTML ( 0 )   PDF(1172KB) ( 126 )   Generation of hyperentangled photon pairs is investigated based on the lithium niobate straight waveguide. We propose to use the nonlinear optical process of spontaneous parametric down-conversion (SPDC) and a well-designed lithium niobate waveguide structure to generate a hyperentangled (in the polarization dimension and the energy-time dimension) two-photon state. By performing numerical simulations of the waveguide structure and calculating the possible polarization states, joint spectral amplitudes (JSA), and joint temporal amplitudes (JTA) of the generated photon pair, we show that the generated photon pair is indeed hyperentangled in both the polarization dimension and the energy-time dimension. 参考文献 | 相关文章 | 计量指标

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Thermodynamic limit of the XXZ central spin model with an arbitrary central magnetic field Fa-Kai Wen(温发楷) and Kun Hao(郝昆) 2023 (9):  90307-090307.  doi: 10.1088/1674-1056/acb426 摘要 ( 212 )   HTML ( 2 )   PDF(950KB) ( 49 )   The U(1) symmetry of the XXZ central spin model with an arbitrary central magnetic field B is broken, since its total spin in the z-direction is not conserved. We obtain the exact solutions of the system by using the off-diagonal Bethe ansatz method. The thermodynamic limit is investigated based on the solutions. We find that the contribution of the inhomogeneous term in the associated T-Q relation to the ground state energy satisfies an N-1 scaling law, where N is the total number of spins. This result makes it possible to investigate the properties of the system in the thermodynamic limit. By assuming the structural form of the Bethe roots in the thermodynamic limit, we obtain the contribution of the direction of B to the ground state energy. It is shown that the contribution of the direction of the central magnetic field is a finite value in the thermodynamic limit. This is the phenomenon caused by the U(1) symmetry breaking of the system. 参考文献 | 相关文章 | 计量指标

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Improved quantum (t,n) threshold group signature Yaodong Zhang(张耀东), Feng Liu(刘锋), and Haixin Zuo(左海新) 2023 (9):  90308-090308.  doi: 10.1088/1674-1056/acac0a 摘要 ( 154 )   HTML ( 1 )   PDF(628KB) ( 52 )   Threshold signature is an important branch of the digital signature scheme, which can distribute signature rights and avoid the abuse of signature rights. With the continuous development of quantum computation and quantum information, quantum threshold signatures are gradually becoming more popular. Recently, a quantum (t,n) threshold group signature scheme was analyzed that uses techniques such as quantum-controlled-not operation and quantum teleportation. However, this scheme cannot resist forgery attack and does not conform to the design of a threshold signature in the signing phase. Based on the original scheme, we propose an improved quantum (t,n) threshold signature scheme using quantum (t,n) threshold secret sharing technology. The analysis proves that the improved scheme can resist forgery attack and collusion attack, and it is undeniable. At the same time, this scheme reduces the level of trust in the arbitrator during the signature phase. 参考文献 | 相关文章 | 计量指标

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Application of Newtonian approximate model to LIGO gravitational wave data processing Jie Wu(吴洁), Jin Li(李瑾), and Qing-Quan Jiang(蒋青权) 2023 (9):  90401-090401.  doi: 10.1088/1674-1056/acd8a3 摘要 ( 233 )   HTML ( 4 )   PDF(2645KB) ( 151 )   With the observation of a series of ground-based laser interferometer gravitational wave (GW) detectors such as LIGO and Virgo, nearly 100 GW events have been detected successively. At present, all detected GW events are generated by the mergers of compact binary systems and are identified through the data processing of matched filtering. Based on matched filtering, we use the GW waveform of the Newtonian approximate (NA) model constructed by linearized theory to {match the events detected by LIGO and injections to determine the coalescence time and} utilize the frequency curve for data fitting to estimate the parameters of the chirp masses of binary black holes (BBHs). The average chirp mass of our results is 22.05-6.31+6.31 M⊙, which is very close to 23.80-3.52+4.83 M⊙ provided by GWOSC. In the process, we can analyze LIGO GW events and estimate the chirp masses of the BBHs. This work presents the feasibility and accuracy of the low-order approximate model and data fitting in the application of GW data processing. It is beneficial for further data processing and has certain research value for the preliminary application of GW data. 参考文献 | 相关文章 | 计量指标

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Dynamics of bubble-shaped Bose-Einstein condensates on two-dimensional cross-section in micro-gravity environment Tie-Fu Zhang(张铁夫), Cheng-Xi Li(李成蹊), and Wu-Ming Liu(刘伍明) 2023 (9):  90501-090501.  doi: 10.1088/1674-1056/acd922 摘要 ( 153 )   HTML ( 4 )   PDF(3958KB) ( 139 )   We investigated the dynamic evolution and interference phenomena of bubble-shaped Bose-Einstein condensates achievable in a micro-gravity environment. Using numerical solutions of the Gross-Pitaevskii equation describing the dynamic evolution of the bubble-shaped Bose-Einstein condensates, we plotted the evolution of the wave function density distribution on its two-dimensional (2D) cross-section and analysed the resulting patterns. We found that changes in the strength of atomic interactions and initial momentum can affect the dynamic evolution of the bubble-shaped Bose-Einstein condensates and their interference fringes. Notably, we have observed that when the initial momentum is sufficiently high, the thickness of the bubble-shaped Bose-Einstein condensate undergoes a counterintuitive thinning, which is a counterintuitive result that requires further investigation. Our findings are poised to advance our comprehension of the physical essence of bubble-shaped Bose-Einstein condensates and to facilitate the development of relevant experiments in micro-gravity environments. 参考文献 | 相关文章 | 计量指标

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Bifurcations for counterintuitive post-inhibitory rebound spike related to absence epilepsy and Parkinson disease Xian-Jun Wang(王宪军), Hua-Guang Gu(古华光), Yan-Bing Jia(贾雁兵), Bo Lu(陆博), and Hui Zhou(周辉) 2023 (9):  90502-090502.  doi: 10.1088/1674-1056/acd7d3 摘要 ( 175 )   HTML ( 5 )   PDF(2309KB) ( 105 )   Seizures are caused by increased neuronal firing activity resulting from reduced inhibitory effect and enhancement of inhibitory modulation to suppress this activity is used as a therapeutic tool. However, recent experiments have shown a counterintuitive phenomenon that inhibitory modulation does not suppress but elicit post-inhibitory rebound (PIR) spike along with seizure to challenge the therapeutic tool. The nonlinear mechanism to avoid the PIR spike can present theoretical guidance to seizure treatment. This paper focuses on identifying credible bifurcations that underlie PIR spike by modulating multiple parameters in multiple theoretical models. The study identifies a codimension-2 bifurcation called saddle-node homoclinic orbit (SNHOB), which is an intersection between saddle node bifurcation on invariant cycle (SNIC) and other two bifurcations. PIR spike cannot be evoked for the SNIC far from the SNHOB but induced for the SNIC close to the SNHOB, which extends the bifurcation condition for PIR spike from the well-known Hopf to SNIC. Especially, in a thalamic neuron model, increases of conductance of T-type Ca2+ (TCa) channel induce SNIC bifurcation approaching to the SNHOB to elicit PIR spikes, closely matching experimental results of the absence seizure or Parkinson diseases. Such results imply that, when inhibition is employed to relieve absence seizure and Parkinson diseases related to PIR spike, modulating SNIC to get far from the SNHOB to avoid PIR spike is the principle. The study also addresses the complex roles of TCa current and comprehensive relationships between PIR spike and nonlinear conceptions such as bifurcation types and shapes of threshold curve. 参考文献 | 相关文章 | 计量指标

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Existence of hidden attractors in nonlinear hydro-turbine governing systems and its stability analysis Peng-Chong Zhao(赵鹏翀), Hao-Juan Wei(卫皓娟), Zhen-Kun Xu(徐振坤), Di-Yi Chen(陈帝伊), Bei-Bei Xu(许贝贝), and Yu-Meng Wang(王雨萌) 2023 (9):  90503-090503.  doi: 10.1088/1674-1056/acc8c4 摘要 ( 140 )   HTML ( 3 )   PDF(2397KB) ( 45 )   This work studies the stability and hidden dynamics of the nonlinear hydro-turbine governing system with an output limiting link, and propose a new six-dimensional system, which exhibits some hidden attractors. The parameter switching algorithm is used to numerically study the dynamic behaviors of the system. Moreover, it is investigated that for some parameters the system with a stable equilibrium point can generate strange hidden attractors. A self-excited attractor with the change of its parameters is also recognized. In addition, numerical simulations are carried out to analyze the dynamic behaviors of the proposed system by using the Lyapunov exponent spectra, Lyapunov dimensions, bifurcation diagrams, phase space orbits, and basins of attraction. Consequently, the findings in this work show that the basins of hidden attractors are tiny for which the standard computational procedure for localization is unavailable. These simulation results are conducive to better understanding of hidden chaotic attractors in higher-dimensional dynamical systems, and are also of great significance in revealing chaotic oscillations such as uncontrolled speed adjustment in the operation of hydropower station due to small changes of initial values. 参考文献 | 相关文章 | 计量指标

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Analytical three-periodic solutions of Korteweg-de Vries-type equations Mi Chen(陈觅) and Zhen Wang(王振) 2023 (9):  90504-090504.  doi: 10.1088/1674-1056/acd9c4 摘要 ( 179 )   HTML ( 9 )   PDF(2345KB) ( 251 )   Based on the direct method of calculating the periodic wave solution proposed by Nakamura, we give an approximate analytical three-periodic solutions of Korteweg-de Vries (KdV)-type equations by perturbation method for the first time. Limit methods have been used to establish the asymptotic relationships between the three-periodic solution separately and another three solutions, the soliton solution, the one- and the two-periodic solutions. Furthermore, it is found that the asymptotic three-soliton solution presents the same repulsive phenomenon as the asymptotic three-soliton solution during the interaction. 参考文献 | 相关文章 | 计量指标

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Critical dispersion of chirped fiber Bragg grating for eliminating time delay signature of distributed feedback laser chaos Da-Ming Wang(王大铭), Yi-Hang Lei(雷一航), Peng-Fei Shi(史鹏飞), and Zhuang-Ai Li(李壮爱) 2023 (9):  90505-090505.  doi: 10.1088/1674-1056/acddce 摘要 ( 193 )   HTML ( 4 )   PDF(1134KB) ( 109 )   Optical chaos has attracted widespread attention owing to its complex dynamic behaviors. However, the time delay signature (TDS) caused by the external cavity mode reduces the complexity of optical chaos. We propose and numerically demonstrate the critical dispersion of chirped fiber Bragg grating (CFBG) for eliminating the TDS of laser chaos in this work. The critical dispersion, as a function of relaxation frequency and bandwidth of the optical spectrum, is found through extensive dynamics simulations. It is shown that the TDS can be eliminated when the dispersion of CFBG is above this critical dispersion. In addition, the influence of dispersive feedback light and output light from a laser is investigated. These results provide important quantitative guidance for designing chaotic semiconductor lasers without TDS. 参考文献 | 相关文章 | 计量指标

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All-electron ZORA triple zeta basis sets for the elements Cs-La and Hf-Rn Antônio Canal Neto, Francisco E. Jorge, and Henrique R. C. da Cruz 2023 (9):  93101-93101.  doi: 10.1088/1674-1056/acbe34 摘要 ( 146 )   HTML ( 1 )   PDF(667KB) ( 19 )   Segmented all-electron basis set of triple zeta valence quality plus polarization functions (TZP) for the elements of the fifth row to be used together with the zero-order regular approximation (ZORA) is carefully constructed. To correctly describe electrons distant from atomic nuclei, the basis set is augmented with diffuse functions giving rise to a set designated as ATZP-ZORA. At the ZORA-B3LYP theoretical level, these sets are used to calculate the ionization energy and mean dipole polarizability of some atoms, bond length, dissociation energy, and harmonic vibrational frequency of diatomic molecules. Then, these results are compared with the theoretical and experimental data found in the literature. Even considering that our sets are relatively compact, they are sufficiently accurate and reliable to perform property calculations involving simultaneously electrons from the inner shell and outer shell. The performances of the ZORA and second-order Douglas-Kroll-Hess Hamiltonians are evaluated and the results are also discussed. 参考文献 | 相关文章 | 计量指标

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Structure and material study of dielectric laser accelerators based on the inverse Cherenkov effect Bin Sun(孙斌), Yang-Fan He(何阳帆), Ruo-Yun Luo(罗若云), Tai-Yang Zhang(章太阳), Qiang Zhou(周强), Shao-Yi Wang(王少义), Du Wang(王度), and Zong-Qing Zhao(赵宗清) 2023 (9):  94101-094101.  doi: 10.1088/1674-1056/acdc0a 摘要 ( 213 )   HTML ( 4 )   PDF(865KB) ( 137 )   Dielectric laser accelerators (DLAs) are considered promising candidates for on-chip particle accelerators that can achieve high acceleration gradients. This study explores various combinations of dielectric materials and accelerated structures based on the inverse Cherenkov effect. The designs utilize conventional processing methods and laser parameters currently in use. We optimize the structural model to enhance the gradient of acceleration and the electron energy gain. To achieve higher acceleration gradients and energy gains, the selection of materials and structures should be based on the initial electron energy. Furthermore, we observed that the variation of the acceleration gradient of the material is different at different initial electron energies. These findings suggest that on-chip accelerators are feasible with the help of these structures and materials. 参考文献 | 相关文章 | 计量指标

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Engineered photonic spin Hall effect of Gaussian beam in antisymmetric parity-time metamaterials Lu-Yao Liu(刘露遥), Zhen-Xiao Feng(冯振校), Dong-Mei Deng(邓冬梅), and Guang-Hui Wang(王光辉) 2023 (9):  94201-094201.  doi: 10.1088/1674-1056/accb89 摘要 ( 176 )   HTML ( 0 )   PDF(2572KB) ( 139 )   A model of the photonic spin Hall effect (PSHE) in antisymmetric parity-time (APT) metamaterials with incidence of Gaussian beams is proposed here. We derive the displacement expression of the PSHE in APT metamaterials based on the transport properties of Gaussian beams in positive and negative refractive index materials. Furthermore, detailed discussions are provided on the APT scattering matrix, eigenstate ratio, and response near exceptional points in the case of loss or gain. In contrast to the unidirectional non-reflection in parity-time (PT) symmetric systems, the transverse shift that arises from both sides of the APT structure is consistent. By effectively adjusting the parameters of APT materials, we achieve giant displacements of the transverse shift. Finally, we present a multi-layer APT structure consisting of alternating left-handed and right-handed materials. By increasing the number of layers, Bragg oscillations can be generated, leading to an increase in resonant peaks in transverse shift. This study presents a new approach to achieving giant transverse shifts in the APT structure. This lays a theoretical foundation for the fabrication of related nano-optical devices. 参考文献 | 相关文章 | 计量指标

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Creation mechanism of electron-positron pair on equally spaced multiple localized fields Chuan-Ke Li(李传可), Nan-Sheng Lin(林南省), Xian-Xian Zhou(周鲜鲜),Miao Jiang(江淼), and Ying-Jun Li(李英骏) 2023 (9):  94202-094202.  doi: 10.1088/1674-1056/acd7cd 摘要 ( 147 )   HTML ( 0 )   PDF(684KB) ( 13 )   We investigate the electron-positron creation process from multiple equally spaced distributed oscillating electric fields. The computational quantum field theory (CQFT) is applied to analyze the effect of the number of local fields, the distance between them, and their potential height on the created particle number. It is found that whether adjacent electric fields overlap plays an important role. The creation rate exhibits a direct linear relationship with the number of fields when they do not overlap, but exceeds the sum of the rate when the fields alone. They exhibit a distinctly nonlinear relationship when they overlap, and in particular exhibit a quadratic relationship when the fields completely overlap. These phenomena corroborate that the particle pair creation in the interaction region is non-uniform and influenced by the strength of the central strongest electric field. 参考文献 | 相关文章 | 计量指标

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Calibration and cancellation of microwave crosstalk in superconducting circuits Haisheng Yan(严海生), Shoukuan Zhao(赵寿宽), Zhongcheng Xiang(相忠诚), Ziting Wang(王子婷), Zhaohua Yang(杨钊华), Kai Xu(许凯), Ye Tian(田野), Haifeng Yu(于海峰), Dongning Zheng(郑东宁), Heng Fan(范桁), and Shiping Zhao(赵士平) 2023 (9):  94203-094203.  doi: 10.1088/1674-1056/acdc10 摘要 ( 279 )   HTML ( 2 )   PDF(2323KB) ( 149 )   The precise control and manipulation of the qubit state are vital for quantum simulation and quantum computation. In superconducting circuits, one notorious error comes from the crosstalk of microwave signals applied to different qubit control lines. In this work, we present a method for the calibration and cancellation of the microwave crosstalk and experimentally demonstrate its effectiveness in a superconducting 10-qubit chain. The method is convenient and efficient especially for calibrating the microwave crosstalk with large amplitudes and variations, which can be performed successively to reduce the microwave crosstalk by two to three orders. The qubit chain with microwave driving is governed by one-dimensional (1D) Bose-Hubbard model in transverse field, which is nonintegrable and shows thermalization behaviour during the time evolution from certain initial states. Such thermalization process is observed with excellent agreement between experiment and theory further confirming the effective global cancellation of the microwave crosstalk. 参考文献 | 相关文章 | 计量指标

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High-speed directly modulated distributed feedback laser based on detuned loading and photon-photon resonance effect Yun-Shan Zhang(张云山), Yi-Fan Xu(徐逸帆), Ji-Lin Zheng(郑吉林), Lian-Yan Li(李连艳), Tao Fang(方涛), and Xiang-Fei Chen(陈向飞) 2023 (9):  94204-094204.  doi: 10.1088/1674-1056/acc8c1 摘要 ( 222 )   HTML ( 0 )   PDF(1849KB) ( 308 )   A monolithic integrated two-section distributed feedback (TS-DFB) semiconductor laser for high-speed direct modulation is proposed and analyzed theoretically. The grating structure of the TS-DFB laser is designed by the reconstruction-equivalent-chirp (REC) technique, which can reduce the manufacturing cost and difficulty, and achieve high wavelength controlling accuracy. The detuned loading effect and the photon-photon resonance (PPR) effect are utilized to enhance the modulation bandwidth of the TS-DFB laser, exceeding 37 GHz, while that of the conventional one-section DFB laser is only 16 GHz. When the bit rate of the non-return-to-zero (NRZ) signal reaches 55 Gb/s, a clear eye diagram with large opening can still be obtained. These results show that the proposed method can enhance the modulation bandwidth of DFB laser significantly. 参考文献 | 相关文章 | 计量指标

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Theory of complex-coordinate transformation acoustics for non-Hermitian metamaterials Hao-Xiang Li(李澔翔), Yang Tan(谭杨), Jing Yang(杨京), and Bin Liang(梁彬) 2023 (9):  94301-094301.  doi: 10.1088/1674-1056/acc3fc 摘要 ( 169 )   HTML ( 1 )   PDF(3726KB) ( 109 )   Transformation acoustics (TA) has emerged as a powerful tool for designing several intriguing conceptual devices, which can manipulate acoustic waves in a flexible manner, yet their applications are limited in Hermitian materials. In this work, we propose the theory of complex-coordinate transformation acoustics (CCTA) and verify the effectiveness in realizing acoustic non-Hermitian metamaterials. Especially, we apply this theory for the first time to the design of acoustic parity-time (PT) and antisymmetric parity-time (APT) metamaterials and demonstrate two distinctive examples. First, we use this method to obtain the exceptional points (EPs) of the PT/APT system and observe the spontaneous phase transition of the scattering matrix in the transformation parameter space. Second, by selecting the Jacobian matrix's constitutive parameters, the PT/APT-symmetric system can also be configured to approach the zero and pole of the scattering matrix, behaving as an acoustic coherent perfect absorber and equivalent laser. We envision our proposed CCTA-based paradigm to open the way for exploring the non-Hermitian physics and finding application in the design of acoustic functional devices such as absorbers and amplifiers whose material parameters are hard to realize by using the conventional transformation method. 参考文献 | 相关文章 | 计量指标

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Dynamics of magnetic microbubble transport in blood vessels Jie Chen(陈杰), Chenghui Wang(王成会), and Runyang Mo(莫润阳) 2023 (9):  94302-094302.  doi: 10.1088/1674-1056/aca14b 摘要 ( 168 )   HTML ( 0 )   PDF(1209KB) ( 35 )   Magnetic microbubbles (MMBs) can be controlled and directed to the target site by a suitable external magnetic field, and thus have potential in therapeutic drug-delivery application. However, few studies focus on their dynamics in blood vessels under the action of magnetic and ultrasonic fields, giving little insight into the mechanism generated in diagnostic and therapeutic applications. In this study, equations of MMBs were established for simulating translation, radial pulsation and the coupled effect of both. Meanwhile, the acoustic streaming and shear stress on the vessel wall were also presented, which are associated with drug release. The results suggest that the magnetic pressure increases the bubble pulsation amplitude, and the translation coupled with pulsation is manipulated by the magnetic force, causing retention in the target area. As the bubbles approach the vessel wall, the acoustic streaming and shear stress increase with magnetic field enhancement. The responses of bubbles to a uniform and a gradient magnetic field were explored in this work. The mathematical models derived in this work could provide theoretical support for experimental phenomena in the literature and also agree with the reported models. 参考文献 | 相关文章 | 计量指标

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Extraction method of nanoparticles concentration distribution from magnetic particle image and its application in thermal damage of magnetic hyperthermia Yundong Tang(汤云东), Ming Chen(陈鸣), Rodolfo C.C. Flesch, and Tao Jin(金涛) 2023 (9):  94401-094401.  doi: 10.1088/1674-1056/acde50 摘要 ( 142 )   HTML ( 0 )   PDF(1781KB) ( 80 )   Magnetic particle imaging (MPI) technology can generate a real-time magnetic nanoparticle (MNP) distribution image for biological tissues, and its use can overcome the limitations imposed in magnetic hyperthermia treatments by the unpredictable MNP distribution after the intratumoral injection of nanofluid. However, the MNP concentration distribution is generally difficult to be extracted from MPI images. This study proposes an approach to extract the corresponding concentration value of each pixel from an MPI image by a least squares method (LSM), which is then translated as MNP concentration distribution by an interpolation function. The resulting MPI-based concentration distribution is used to evaluate the treatment effect and the results are compared with the ones of two baseline cases under the same dose: uniform distribution and MPI-based distribution considering diffusion. Additionally, the treatment effect for all these cases is affected by the blood perfusion rate, which is also investigated deeply in this study. The results demonstrate that the proposed method can be used to effectively reconstruct the concentration distribution from MPI images, and that the weighted LSM considering a quartic polynomial for interpolation provides the best results with respect to other cases considered. Furthermore, the results show that the uniformity of MNP distribution has a positive correlation with both therapeutic temperature distribution and thermal damage degree for the same dose and a critical power dissipation value in the MNPs. The MNPs uniformity inside biological tissue can be improved by the diffusion behavior after the nanofluid injection, which can ultimately reflect as an improvement of treatment effect. In addition, the blood perfusion rate considering local temperature can have a positive effect on the treatment compared to the case which considers a constant value during magnetic hyperthermia. 参考文献 | 相关文章 | 计量指标

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Application of shifted lattice model to 3D compressible lattice Boltzmann method Hao-Yu Huang(黄好雨), Ke Jin(金科), Kai Li(李凯), and Xiao-Jing Zheng(郑晓静) 2023 (9):  94701-094701.  doi: 10.1088/1674-1056/acc78d 摘要 ( 166 )   HTML ( 0 )   PDF(1708KB) ( 63 )   An additional potential energy distribution function is introduced on the basis of previous D3Q25 model, and the equilibrium distribution function of D3Q25 is obtained by spherical function. A novel three-dimensional (3D) shifted lattice model is proposed, therefore a shifted lattice model is introduced into D3Q25. Under the finite volume scheme, several typical compressible calculation examples are used to verify whether the numerical stability of the D3Q25 model can be improved by adding the shifted lattice model. The simulation results show that the numerical stability is indeed improved after adding the shifted lattice model. 参考文献 | 相关文章 | 计量指标

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Discussion on interface deformation and liquid breakup mechanism in vapor-liquid two-phase flow Xiang An(安祥), Bo Dong(董波), Ya-Jin Zhang(张雅瑾), and Xun Zhou(周训) 2023 (9):  94702-094702.  doi: 10.1088/1674-1056/acc78e 摘要 ( 157 )   HTML ( 0 )   PDF(2252KB) ( 80 )   The interface deformation and liquid breakup in vapor-liquid two-phase flow are ubiquitous in natural phenomena and industrial applications. It is crucial to understand the corresponding mechanism correctly. The droplet and liquid ligament dynamic behaviors are investigated in this work by simulating three benchmark cases through adopting a three-dimensional (3D) phase-field-based lattice Boltzmann model, and vapor-liquid phase interface deformation and liquid breakup mechanisms including the capillary instability and end-pinching mechanism are analyzed. The analysis results show that the capillary instability is the driving mechanism of the liquid breakup and the secondary droplet production at a large Weber number, which is different from the Rayleigh-Taylor instability and Kelvin-Helmholtz instability characterizing the vapor-liquid interface deformation. In addition, as another liquid breakup mechanism, the end-pinching mechanism, which describes the back-flow phenomenon of the liquid phase, works at each breakup point, thus resulting in capillary instability on the liquid phase structure. In essence, it is the fundamental mechanism for the liquid breakup and the immanent cause of capillary instability. 参考文献 | 相关文章 | 计量指标

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Theoretical analyses on the one-dimensional charged particle transport in a decaying plasma under an electrostatic field Yao-Ting Wang(汪耀庭), Xin-Li Sun(孙鑫礼), Lan-Yue Luo(罗岚月), Zi-Ming Zhang(张子明), He-Ping Li(李和平), Dong-Jun Jiang(姜东君), and Ming-Sheng Zhou(周明胜) 2023 (9):  95201-095201.  doi: 10.1088/1674-1056/ace033 摘要 ( 161 )   HTML ( 0 )   PDF(2192KB) ( 178 )   The spatiotemporal evolutions of a one-dimensional collisionless decaying plasma bounded by two electrodes with an externally applied electrostatic field are studied by theoretical analyses and particle-in-cell (PIC) simulations with the ion extraction process in a laser-induced plasma as the major research background. Based on the theoretical analyses, the transport process of the charged particles including electrons and ions can be divided into three stages: electron oscillation and ion matrix sheath extraction stage, sheath expansion and ion rarefaction wave propagation stage and the plasma collapse stage, and the corresponding criterion for each stage is also presented. Consequently, a complete analytical model is established for describing the ion extraction flux at each stage during the decaying of the laser-induced plasmas under an electrostatic field, which is also validated by the PIC modeling results. Based on this analytical model, influences of the key physical parameters, including the initial electron temperature and number density, plasma width and the externally applied electric voltage, on the ratio of the extracted ions are predicted. The calculated results show that a higher applied electric potential, smaller initial plasma number density and plasma width lead to a higher ratio of the extracted ions during the first stage; while in this stage, the initial electron temperature shows little effect on it. Meanwhile, more ions will be extracted before the plasma collapse once a higher electric potential is applied. The theoretical model presented in this paper is helpful not only for a deep understanding to the charged particle transport mechanisms for a bounded decaying plasma under an applied electrostatic field, but also for an optimization of the ion extraction process in practical applications. 参考文献 | 相关文章 | 计量指标

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Effect of sharp vacuum-plasma boundary on the electron injection and acceleration in a few-cycle laser driven wakefield Guo-Bo Zhang(张国博), Song Liu(刘松), De-Bin Zou(邹德滨), Ye Cui(崔野), Jian-Peng Liu(刘建鹏), Xiao-Hu Yang(杨晓虎), Yan-Yun Ma(马燕云), and Fu-Qiu Shao(邵福球) 2023 (9):  95202-095202.  doi: 10.1088/1674-1056/acdc0c 摘要 ( 155 )   HTML ( 0 )   PDF(2111KB) ( 120 )   The electron injection and acceleration driven by a few-cycle laser with a sharp vacuum-plasma boundary have been investigated through three-dimensional (3D) particle-in-cell simulations. It is found that an isotropic boundary impact injection (BII) first occurs at the vacuum-plasma boundary, and then carrier-envelope-phase (CEP) shift causes the transverse oscillation of the plasma bubble, resulting in a periodic electron self-injection (SI) in the laser polarization direction. It shows that the electron charge of the BII only accounts for a small part of the total charge, and the CEP can effectively tune the quality of the injected electron beam. The dependences of laser intensity and electron density on the total charge and the ratio of BII charge to the total charge are studied. The results are beneficial to electron acceleration and its applications, such as betatron radiation source. 参考文献 | 相关文章 | 计量指标

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Flow control performance evaluation of a tri-electrode sliding discharge plasma actuator Borui Zheng(郑博睿), Yuanpeng Liu(刘园鹏), Minghao Yu(喻明浩), Yuanzhong Jin(金元中),Qian Zhang(张倩), and Quanlong Chen(陈全龙) 2023 (9):  95203-095203.  doi: 10.1088/1674-1056/acae76 摘要 ( 124 )   HTML ( 3 )   PDF(1287KB) ( 26 )   Tri-electrode sliding discharge (TED) plasma actuators are formed by adding a direct current (DC) exposed electrode to conventional dielectric barrier discharge (DBD) plasma actuators. There are three TED modes depending on the polarity and amplitude of the DC supply: DBD discharge, extended discharge and sliding discharge. This paper evaluates the electrical, aerodynamic and mechanical characteristics of a TED plasma actuator based on energy analysis, particle image velocimetry experiments and calculations using the Navier-Stokes equation. The flow control performances of different discharge modes are quantitatively analyzed based on characteristic parameters. The results show that flow control performance in both extended discharge and sliding discharge is more significant than that of DBD, mainly because of the significantly higher (up to 141%) body force of TED compared with DBD. However, conductivity loss is the primary power loss caused by the DC polarity for TED discharge. Therefore, power consumption can be reduced by optimizing the dielectric material and thickness, thus improving the flow control performance of plasma actuators. 参考文献 | 相关文章 | 计量指标

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Classification and structural characteristics of amorphous materials based on interpretable deep learning Jiamei Cui(崔佳梅), Yunjie Li(李韵洁), Cai Zhao(赵偲), and Wen Zheng(郑文) 2023 (9):  96101-096101.  doi: 10.1088/1674-1056/acd7d0 摘要 ( 164 )   HTML ( 1 )   PDF(3900KB) ( 95 )   Defining the structure characteristics of amorphous materials is one of the fundamental problems that need to be solved urgently in complex materials because of their complex structure and long-range disorder. In this study, we develop an interpretable deep learning model capable of accurately classifying amorphous configurations and characterizing their structural properties. The results demonstrate that the multi-dimensional hybrid convolutional neural network can classify the two-dimensional (2D) liquids and amorphous solids of molecular dynamics simulation. The classification process does not make a priori assumptions on the amorphous particle environment, and the accuracy is 92.75%, which is better than other convolutional neural networks. Moreover, our model utilizes the gradient-weighted activation-like mapping method, which generates activation-like heat maps that can precisely identify important structures in the amorphous configuration maps. We obtain an order parameter from the heatmap and conduct finite scale analysis of this parameter. Our findings demonstrate that the order parameter effectively captures the amorphous phase transition process across various systems. These results hold significant scientific implications for the study of amorphous structural characteristics via deep learning. 参考文献 | 相关文章 | 计量指标

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Investigation of heavy ion irradiation effects on a charge trapping memory capacitor by bm C-V measurement Qiyu Chen(陈麒宇), Xirong Yang(杨西荣), Zongzhen Li(李宗臻), Jinshun Bi(毕津顺), Kai Xi(习凯),Zhenxing Zhang(张振兴), Pengfei Zhai(翟鹏飞), Youmei Sun(孙友梅), and Jie Liu(刘杰) 2023 (9):  96102-096102.  doi: 10.1088/1674-1056/acae78 摘要 ( 168 )   HTML ( 0 )   PDF(839KB) ( 87 )   Heavy ion irradiation effects on charge trapping memory (CTM) capacitors with TiN/Al2O3/HfO2/Al2O3/HfO2/ SiO2/p-Si structure have been investigated. The ion-induced interface charges and oxide trap charges were calculated and analyzed by capacitance-voltage (C-V) characteristics. The C-V curves shift towards the negative direction after swift heavy ion irradiation, due to the net positive charges accumulating in the trapping layer. The memory window decreases with the increase of ion fluence at high voltage, which results from heavy ion-induced structural damage in the blocking layer. The mechanism of heavy ion irradiation effects on CTM capacitors is discussed in detail with energy band diagrams. The results may help to better understand the physical mechanism of heavy ion-induced degradation of CTM capacitors. 参考文献 | 相关文章 | 计量指标

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Pressure induced insulator to metal transition in quantum spin liquid candidate NaYbS2 Yating Jia(贾雅婷), Chunsheng Gong(龚春生), Zhiwen Li(李芷文), Yixuan Liu(刘以轩), Jianfa Zhao(赵建发), Zhe Wang(王哲), Hechang Lei(雷和畅), Runze Yu(于润泽), and Changqing Jin(靳常青) 2023 (9):  96201-096201.  doi: 10.1088/1674-1056/accff0 摘要 ( 171 )   HTML ( 0 )   PDF(901KB) ( 94 )   Pressure induced insulator to metal transition followed by the appearance of superconductivity has been observed recently in inorganic quantum spin liquid candidate NaYbSe2. In this paper, we study the properties of isostructural compound NaYbS2 under pressure. It is found that the resistance of NaYbS2 single crystal exhibits an insulating state below 82.9 GPa, but with a drop of more than six orders of magnitude at room temperature. Then a minimum of resistance is observed at about 100.1 GPa and it moves to lower temperature with further compression. Finally, a metallic state in the whole temperature range is observed at about 130.3 GPa accompanied by a non-Fermi liquid behavior below 100 K. The insulator to metal transition, non-monotonic resistance feature and non-Fermi liquid behavior of NaYbS2 under pressure are similar to those of NaYbSe2, suggesting that these phenomena might be the universal properties in NaLnCh2 (Ln = rare earth, Ch = O, S, Se) system. 参考文献 | 相关文章 | 计量指标

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Unveiling phonon frequency-dependent mechanism of heat transport across stacking fault in silicon carbide Fu Wang(王甫), Yandong Sun(孙彦东), Yu Zou(邹宇), Ben Xu(徐贲), and Baoqin Fu(付宝勤) 2023 (9):  96301-096301.  doi: 10.1088/1674-1056/acdfc0 摘要 ( 153 )   HTML ( 0 )   PDF(1276KB) ( 77 )   Stacking faults (SFs) are often present in silicon carbide (SiC) and affect its thermal and heat-transport properties. However, it is unclear how SFs influence thermal transport. Using non-equilibrium molecular dynamics and lattice dynamics simulations, we studied phonon transport in SiC materials with an SF. Compared to perfect SiC materials, the SF can reduce thermal conductivity. This is caused by the additional interface thermal resistance (ITR) of SF, which is difficult to capture by the previous phenomenological models. By analyzing the spectral heat flux, we find that SF reduces the contribution of low-frequency (7.5 THz-12 THz) phonons to the heat flux, which can be attributed to SF reducing the phonon lifetime and group velocity, especially in the low-frequency range. The SF hinders phonon transport and results in an effective interface thermal resistance around the SF. Our results provide insight into the microscopic mechanism of the effect of defects on heat transport and have guiding significance for the regulation of the thermal conductivity of materials. 参考文献 | 相关文章 | 计量指标

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New carbon-nitrogen-oxygen compounds as high energy density materials Junyu Shen(沈俊宇), Qingzhuo Duan(段青卓), Junyi Miao(苗俊一), Shi He(何适),Kaihua He(何开华), Wei Dai(戴伟), and Cheng Lu(卢成) 2023 (9):  96302-096302.  doi: 10.1088/1674-1056/acce94 摘要 ( 186 )   HTML ( 1 )   PDF(1000KB) ( 253 )   Molecular crystals are complex systems exhibiting various crystal structures, and accurately modeling the crystal structures is essential for understanding their physical behaviors under high pressure. Here, we perform an extensive structure search of ternary carbon-nitrogen-oxygen (CNO) compound under high pressure with the CALYPSO method and first principles calculations, and successfully identify three polymeric CNO compounds with Pbam, C2/m and I$\overline 4 $m2 symmetries under 100 GPa. More interestingly, these structures are also dynamically stable at ambient pressure, and are potential high energy density materials (HEDMs). The energy densities of Pbam, C2/m and I$\overline 4 $m2 phases of CNO are about 2.30 kJ/g, 1.37 kJ/g and 2.70 kJ/g, respectively, with the decompositions of graphitic carbon and molecular carbon dioxide and α-N (molecular N2) at ambient pressure. The present results provide in-depth insights into the structural evolution and physical properties of CNO compounds under high pressures, which offer crucial insights for designs and syntheses of novel HEDMs. 参考文献 | 相关文章 | 计量指标

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Super-ballistic diffusion in a quasi-periodic non-Hermitian driven system with nonlinear interaction Jian-Zheng Li(李建政), Guan-Ling Li(李观玲), and Wen-Lei Zhao(赵文垒) 2023 (9):  96601-096601.  doi: 10.1088/1674-1056/acd2af 摘要 ( 148 )   HTML ( 0 )   PDF(1274KB) ( 129 )   We investigate the effects of nonlinear interactions on quantum diffusion in a quasi-periodic quantum kicked rotor system, featuring a non-Hermitian kicking potential. Remarkably, when the non-Hermitian driving strength is sufficiently strong, the energy diffusion follows a power law of time, characterized by an exponent that decreases monotonically with increasing the strength of nonlinear interactions. This demonstrates the emergence of super-ballistic diffusion (SBD). We find a distinct prethermalization stage in the time domain preceding the onset of SBD. The unique quantum diffusion phenomena observed in this chaotic system can be attributed to the decoherence effects generated by the interplay between nonlinear interactions and the non-Hermitian kicking potential. 参考文献 | 相关文章 | 计量指标

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Manipulating charge density wave state in kagome compound RbV3Sb5 Yu-Xin Meng(孟雨欣), Cheng-Long Xue(薛成龙), Li-Guo Dou(窦立国), Wei-Min Zhao(赵伟民), Qi-Wei Wang(汪琪玮), Yong-Jie Xu(徐永杰), Xiangqi Liu(刘祥麒), Wei Xia(夏威), Yanfeng Guo(郭艳峰), and Shao-Chun Li(李绍春) 2023 (9):  96801-096801.  doi: 10.1088/1674-1056/acd8b1 摘要 ( 213 )   HTML ( 4 )   PDF(2094KB) ( 162 )   Owing to the unique electronic structure, kagome materials AV3Sb5 (A=K, Rb, Cs) provide a fertile platform of quantum phenomena such as the strongly correlated state and topological Dirac band. It is well known that RbV3Sb5 exhibits a 2×2 unconventional charge density wave (CDW) state at low temperature, and the mechanism is controversial. Here, by using scanning tunneling microscopy/spectroscopy (STM/STS), we successfully manipulated the CDW state in the Sb plane of RbV3Sb5, and realized a new sqrt $\sqrt 3 $×$\sqrt 3 $ modulation together with the ubiquitous 2×2 period in the CDW state of RbV3Sb5. This work provides a new understanding of the collective quantum ground states in the kagome materials. 参考文献 | 相关文章 | 计量指标

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Adsorption structure of macrocyclic energetic molecule DOATF on Au(111) Xiao Chang(常霄), Li Huang(黄立), Yixuan Gao(高艺璇), Changjiang Yu(于长江), Yun Cao(曹云), Long Lv(吕龙), Xiao Lin(林晓), Shixuan Du(杜世萱), and Hong-Jun Gao(高鸿钧) 2023 (9):  96802-096802.  doi: 10.1088/1674-1056/acda84 摘要 ( 188 )   HTML ( 2 )   PDF(1396KB) ( 122 )   Furazan macrocyclic compound 3,4:7,8:11,12:15,16-tetrafurazan-1,9-dioxazo-5,13- diazocyclohexadecane (DOATF) is an ideal energetic material with high heat of formation. Here, using scanning tunneling microscopy (STM) and non-contact atomic force microscopy (nc-AFM), we investigated the adsorption structure of DOATF molecules on Au(111) surface, which shows the four furanzan rings in the STM images and a bright protrusion off the center of the molecule in the nc-AFM images. Combined with density functional theory (DFT) calculations, we confirmed that the bright feature in the nc-AFM images is an N-O coordinate bond pointing upwards in one of the two azoxy groups; while the other N-O bond pointing towards the Au(111) surface. Our work contributes for a deeper understanding of the adsorption structure of macrocyclic compounds, which would promote the designing of DOATF-metal frameworks. 参考文献 | 相关文章 | 计量指标

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Design of sign-reversible Berry phase effect in 2D magneto-valley material Yue-Tong Han(韩曰通), Yu-Xian Yang(杨宇贤), Ping Li(李萍), and Chang-Wen Zhang(张昌文) 2023 (9):  97101-097101.  doi: 10.1088/1674-1056/acd920 摘要 ( 177 )   HTML ( 0 )   PDF(6953KB) ( 117 )   Manipulating sign-reversible Berry phase effects is both fundamentally intriguing and practically appealing for searching for exotic topological quantum states. However, the realization of multiple Berry phases in the magneto-valley lattice is rather challenging due to the complex interactions from spin-orbit coupling (SOC), band topology, and magnetic ordering. Here, taking single-layer spin-valley RuCl2 as an example, we find that sign-reversible Berry phase transitions from ferrovalley (FV) to half-valley semimetal (HVS) to quantum anomalous valley Hall effect (QAVHE) can be achieved via tuning electronic correlation effect or biaxial strains. Remarkably, QAVHE phase, which combines both the features of quantum anomalous Hall and anomalous Hall valley effect, is introduced by sign-reversible Berry curvature or band inversion of dxy/dx2-y2 and dz2 orbitals at only one of the K/K' valleys of single-layer RuCl2. And the boundary of QAVHE phase is the HVS state, which can achieve 100% intrinsically valley polarization. Further, a k·p model unveiled the valley-controllable sign-reversible Berry phase effects. These discoveries establish RuCl2 as a promising candidate to explore exotic quantum states at the confluence of nontrivial topology, electronic correlation, and valley degree of freedom. 参考文献 | 补充材料 | 相关文章 | 计量指标

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Infrared optical absorption of Fröhlich polarons in metal halide perovskites Yu Cui(崔钰), Xiao-Yi Liu(刘晓逸), Xu-Fei Ma(马旭菲), Jia-Pei Deng(邓加培), Yi-Yan Liu(刘怡言), and Zi-Wu Wang(王子武) 2023 (9):  97102-097102.  doi: 10.1088/1674-1056/aca7f0 摘要 ( 195 )   HTML ( 2 )   PDF(1379KB) ( 20 )   The formation of Fröhlich polarons in metal halide perovskites, arising from the charge carrier-longitudinal optical (LO) phonon coupling, has been proposed to explain their exceptional properties, but the effective identification of polarons in these materials is still a challenging task. Herein, we theoretically present the infrared optical absorption of Fröhlich polarons based on the Huang-Rhys model. We find that multiphonon overtones appear as the energy of the incident photons matches the multiple LO phonons, wherein the average phonon number of a polaron can be directly evaluated by the order of the strongest overtone. These multiphonon structures sensitively depend on the scale of electronic distribution in the ground state and the dimensionality of the perovskite materials, revealing the effective modulation of competing processes between polaron formation and carrier cooling. Moreover, the order of the strongest overtone shifts to higher ones with temperature, providing a potential proof that the carrier mobility is affected by LO phonon scattering. The present model not only suggests a direct way to verify Fröhlich polarons but also enriches our understanding of the properties of polarons in metal halide perovskites. 参考文献 | 补充材料 | 相关文章 | 计量指标

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Electronic structure study of the charge-density-wave Kondo lattice CeTe3 Bo Wang(王博), Rui Zhou(周锐), Xuebing Luo(罗学兵), Yun Zhang(张云), and Qiuyun Chen(陈秋云) 2023 (9):  97103-097103.  doi: 10.1088/1674-1056/acb41e 摘要 ( 149 )   HTML ( 0 )   PDF(2509KB) ( 124 )   The behaviors of m f electrons are crucial for understanding the rich phase diagrams and ground-state properties of heavy fermion (HF) systems. The complicated interactions between m f electrons and conduction electrons largely enrich the basic properties of HF compounds. Here the electronic structure, especially the m f-electron character, of the charge-density-wave (CDW) Kondo lattice compound CeTe3 has been studied by high-resolution angle-resolved photoemission spectroscopy. A weakly dispersive quasiparticle band near the Fermi level has been observed directly, indicating hybridization between m f electrons and conduction electrons. Temperature-dependent measurements confirm the localized to itinerant transition of m f electrons as the temperature decreases. Furthermore, an energy gap formed by one conduction band at low temperature is gradually closed with increasing temperature, which probably originates from the CDW transition at extremely high temperature. Additionally, orbital information of different electrons has also been acquired with different photon energies and polarizations, which indicates the anisotropy and diverse symmetries of the orbitals. Our results may help understand the complicated m f-electron behaviors when considering its interaction with other electrons/photons in CeTe3 and other related compounds. 参考文献 | 相关文章 | 计量指标

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Doping tuned anomalous Hall effect in the van der Waals magnetic topological phases Mn(Sb1-xBix)4Te7 Xin Zhang(张鑫), Zhicheng Jiang(江志诚), Jian Yuan(袁健), Xiaofei Hou(侯骁飞), Xia Wang(王霞),Na Yu(余娜), Zhiqiang Zou(邹志强), Zhengtai Liu(刘正太), Wei Xia(夏威),Zhenhai Yu(于振海), Dawei Shen(沈大伟), and Yanfeng Guo(郭艳峰) 2023 (9):  97201-097201.  doi: 10.1088/1674-1056/acd629 摘要 ( 206 )   HTML ( 0 )   PDF(811KB) ( 279 )   The van der Waals (vdW) MnSb4Te7 is a newly synthesized antiferromagnetic (AFM) topological insulator hosting a robust axion insulator state irrelative to the specific spin structure. However, the intrinsic hole doped character of MnSb4Te7 makes the Fermi level far away from the Dirac point of about 180 meV, which is unfavorable for the exploration of exotic topological properties such as the quantum anomalous Hall effect (QAHE). To shift up the Fermi level close to the Dirac point, the strategy of partially replacing Sb with Bi as Mn(Sb1-xBix)4Te7 was tried and the magnetotransport properties, in particular, the anomalous Hall effect, were measured and analyzed. Through the electron doping, the anomalous Hall conductance σAH changes from negative to positive between x = 0.3 and 0.5, indicative of a possible topological transition. Besides, a charge neutrality point (CNP) also appears between x = 0.6 and 0.7. The results would be instructive for further understanding the interplay between nontrivial topological states and the magnetism, as well as for the exploration of exotic topological properties. 参考文献 | 补充材料 | 相关文章 | 计量指标

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Experimental and theoretical investigations of the photoelectrochemical and photo-Fenton properties of Co-doped FeOCl Jin-Huan Ma(马金环), Zhi-Qiang Wei(魏智强), Mei-Jie Ding(丁梅杰),Ji-Wei Zhao(赵继威), and Cheng-Gong Lu(路承功) 2023 (9):  97202-097202.  doi: 10.1088/1674-1056/acae7f 摘要 ( 141 )   HTML ( 1 )   PDF(1806KB) ( 86 )   For the first time, two-dimensional FeOCl (Fe1-xCoxOCl) doped with Co was successfully applied to the photocatalytic and photo-Fenton degradation of Rhodamine B (RhB). The photocatalytic and photo-Fenton experiments showed that the degradation rates of RhB by Fe0.94Co0.06OCl are 82.6% and 98.2% within 50 min under neutral solution, room temperature and visible light. The inclusion of Co resulted in lattice imperfections on the surface of FeOCl, which was advantageous for the photogenerated electron-hole pair separation efficiency (consistent with the density functional theory calculation). Moreover, the RhB removal rate decreased from 98% to 82% during five successive cycles, showing good structural stability. Finally, based on the radical capture experiment, a potential mechanism for RhB degradation by Fe1-xCoxOCl catalyst was proposed. The idea of a synergistic mechanism for Fe1-xCoxOCl also offers a fresh concept for catalysts used in doping modification. 参考文献 | 相关文章 | 计量指标

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Design optimization of a silicon-germanium heterojunction negative capacitance gate-all-around tunneling field effect transistor based on a simulation study Weijie Wei(魏伟杰), Weifeng Lü(吕伟锋), Ying Han(韩颖), Caiyun Zhang(张彩云), and Dengke Chen(谌登科) 2023 (9):  97301-097301.  doi: 10.1088/1674-1056/acaa2c 摘要 ( 192 )   HTML ( 1 )   PDF(2753KB) ( 93 )   The steep sub-threshold swing of a tunneling field-effect transistor (TFET) makes it one of the best candidates for low-power nanometer devices. However, the low driving capability of TFETs prevents their application in integrated circuits. In this study, an innovative gate-all-around (GAA) TFET, which represents a negative capacitance GAA gate-to-source overlap TFET (NCGAA-SOL-TFET), is proposed to increase the driving current. The proposed NCGAA-SOL-TFET is developed based on technology computer-aided design (TCAD) simulations. The proposed structure can solve the problem of the insufficient driving capability of conventional TFETs and is suitable for sub-3-nm nodes. In addition, due to the negative capacitance effect, the surface potential of the channel can be amplified, thus enhancing the driving current. The gate-to-source overlap (SOL) technique is used for the first time in an NCGAA-TFET to increase the band-to-band tunneling rate and tunneling area at the silicon-germanium heterojunction. By optimizing the design of the proposed structure via adjusting the SOL length and the ferroelectric layer thickness, a sufficiently large on-state current of 17.20 upmu A can be achieved and the threshold voltage can be reduced to 0.31 V with a sub-threshold swing of 44.98 mV/decade. Finally, the proposed NCGAA-SOL-TFET can overcome the Boltzmann limit-related problem, achieving a driving current that is comparable to that of the traditional complementary metal-oxide semiconductor devices. 参考文献 | 相关文章 | 计量指标

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Resistive switching properties of SnO2 nanowires fabricated by chemical vapor deposition Ya-Qi Chen(陈亚琦), Zheng-Hua Tang(唐政华), Chun-Zhi Jiang(蒋纯志), and De-Gao Xu(徐徳高) 2023 (9):  97302-097302.  doi: 10.1088/1674-1056/acc3fd 摘要 ( 159 )   HTML ( 0 )   PDF(4276KB) ( 46 )   Resistive switching (RS) devices have great application prospects in the emerging memory field and neuromorphic field, but their stability and unclear RS mechanism limit their relevant applications. In this work, we construct a hydrogenated Au/SnO2 nanowire (NW)/Au device with two back-to-back Schottky diodes and investigate the RS characteristics in air and vacuum. We find that the Ion/Ioff ratio increases from 20 to 104 when the read voltage decreases from 3.1 V to -1 V under the condition of electric field. Moreover, the rectification ratio can reach as high as 104 owing to oxygen ion migration modulated by the electric field. The nanodevice also shows non-volatile resistive memory characteristic. The RS mechanism is clarified based on the changes of the Schottky barrier width and height at the interface of Au/SnO2 NW/Au device. Our results provide a strategy for designing high-performance memristive devices based on SnO2 NWs. 参考文献 | 相关文章 | 计量指标

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Multi-band analysis on physical properties of superconducting FeSe films Jian-Tao Che(车剑韬) and Chen-Xiao Ye(叶晨骁) 2023 (9):  97401-097401.  doi: 10.1088/1674-1056/acd3e5 摘要 ( 135 )   HTML ( 0 )   PDF(537KB) ( 32 )   The origins of superconductivity and pairing symmetry of order parameters are still controversial problems for FeSe thin films up to date. Under the Neumann boundary conditions, the electromagnetic properties of this system are investigated using the two-band Ginzburg-Landau theory. We calculate the temperature dependence of upper critical field in arbitrary direction and critical supercurrent density through the FeSe film. It is revealed that the normalized upper critical field is independent of the film thickness and all of our theoretical results are in accordance with the experimental data. These thus strongly indicate the existence of two-gap s-wave superconductivity in this material. 参考文献 | 相关文章 | 计量指标

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A ten-fold coordinated high-pressure structure in hafnium dihydrogen with increasing superconducting transition temperature induced by enhancive pressure Yan-Qi Wang(王妍琪), Chuan-Zhao Zhang(张传钊), Jin-Quan Zhang(张金权), Song Li(李松), Meng Ju(巨濛), Wei-Guo Sun(孙伟国), Xi-Long Dou(豆喜龙), and Yuan-Yuan Jin(金园园) 2023 (9):  97402-097402.  doi: 10.1088/1674-1056/acc934 摘要 ( 177 )   HTML ( 0 )   PDF(1725KB) ( 171 )   High pressure is an effective method to induce structural and electronic changes, creating novel high-pressure structures with excellent physical and chemical properties. Herein, we investigate the structural phase transition of hafnium dihydrogen (HfH2) in a pressure range of 0 GPa-500 GPa through the first-principles calculations and the crystal structure analysis by particle swarm optimization (CALYPSO) code. The high-pressure phase transition sequence of HfH2 is I4/mmm→Cmma→P-3m1 and the two phase transition pressure points are 220.21 GPa and 359.18 GPa, respectively. A newly trigonal P-3m1 structure with 10-fold coordination first appears as an energy superior structure under high pressure. These three structures are all metallic with the internal ionic bonding of Hf and H atoms. Moreover, the superconducting transition temperature (Tc) values of Cmma at 300 GPa and P-3m1 at 500 GPa are 3.439 K and 19.737 K, respectively. Interestingly, the superconducting transition temperature of the P-3m1 structure presents an upward trend with the pressure rising, which can be attributed to the increase of electron-phonon coupling caused by the enhanced Hf-d electronic density of states at Fermi level under high pressure. 参考文献 | 补充材料 | 相关文章 | 计量指标

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Hole density dependent magnetic structure and anisotropy in Fe-pnictide superconductor Yuan-Fang Yue(岳远放), Zhong-Bing Huang(黄忠兵), Huan Li(黎欢),Xing Ming(明 星), and Xiao-Jun Zheng(郑晓军) 2023 (9):  97403-097403.  doi: 10.1088/1674-1056/acd328 摘要 ( 135 )   HTML ( 0 )   PDF(802KB) ( 74 )   The competition between different magnetic structures in hole-doped Fe-pnicitides is explored based on an extended five-orbital Hubbard model including long-range Coulomb interactions. Our results show that the stabilized magnetic structure evolves with increasing hole doping level. Namely, the stripe antiferromagnetic phase dominates at zero doping, while magnetic structures with more antiferromagnetic linking numbers such as the staggered tetramer, staggered trimer, and staggered dimer phases become energetically favorable as the hole density increases. At a certain doping level, energy degeneracy of different magnetic structures appears, indicating strong magnetic frustration and magnetic fluctuations in the system. We suggest that the magnetic competition induced by the hole doping may explain the fast decrease of the Neel temperature TN and the moderately suppressed magnetic moment in the hole doped Fe-pnicitides. Moreover, our results show a sign reversal of the kinetic energy anisotropy as the magnetic ground state evolves, which may be the mechanism behind the puzzling sign reversal of the in-plane resistivity anisotropy in hole-doped Fe-pnicitides. 参考文献 | 相关文章 | 计量指标

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Tuning magneto-dielectric properties of Co2Z ferrites via Gd doping for high-frequency applications Jian Wu(武剑), Bing Lu(卢冰), Ying Zhang(张颖), Yixin Chen(陈一鑫), Kai Sun(孙凯), Daming Chen(陈大明), Qiang Li(李强), Yingli Liu(刘颖力), and Jie Li(李颉) 2023 (9):  97501-097501.  doi: 10.1088/1674-1056/acc3f7 摘要 ( 176 )   HTML ( 0 )   PDF(9185KB) ( 52 )   Magneto-dielectric properties of Co2Z ferrite materials are tuned via Gd doping for applications in high-frequency antennas and filters in the present work. Ba3Co2Fe24-xGdxO41 (x = 0.00, 0.05, 0.10, 0.15, and 0.20) materials are successfully prepared by using solid-state method at 925 ℃ for 4 h with 2.5-wt% Bi2O3 sintering aids. The content of Gd3+ ion can affect micromorphology, grain size, bulk density, and magneto-dielectric properties of the ferrite. With Gd3+ ion content increasing, saturation magnetization (Ms) first increases and then decreases. The maximum value of Ms is 44.86 emu/g at x =0.15. Additionally, sites occupied by Gd3+ ions can change magnetic anisotropy constant of the ferrite. Magnetocrystalline anisotropy constant (K1) is derived from initial magnetization curve, and found to be related to spin-orbit coupling and intersublattice interactions between metal ions. The real part of magnetic permeability (μ') and real part of dielectric permittivity (ε') are measured in a frequency range of 10 MHz-1 GHz. When x =0.15, material has excellent magneto-dielectric properties (μ' ≈ 12.2 and ε' ≈ 17.61), low magnetic loss (tan δμ ≈ 0.03 at 500 MHz), and dielectric loss (tan δε ≈ 0.04 at 500 MHz). The results show that Gd-doped Co2Z ferrite has broad application prospects in multilayer filters and high-frequency antennas. 参考文献 | 相关文章 | 计量指标

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Magnetic-field-controlled spin valve and spin memory based on single-molecule magnets Zhengzhong Zhang(张正中), Ruya Guo(郭儒雅), Rui Bo(薄锐), and Hao Liu(刘昊) 2023 (9):  97502-097502.  doi: 10.1088/1674-1056/accf7c 摘要 ( 188 )   HTML ( 0 )   PDF(779KB) ( 66 )   A single-molecule magnet is a long-sought-after nanoscale component because it can enable us to miniaturize nonvolatile memory storage devices. The signature of a single-molecule magnet is switching between two bistable magnetic ground states under an external magnetic field. Based on this feature, we theoretically investigate a magnetic-field-controlled reversible resistance change active at low temperatures in a molecular magnetic tunnel junction, which consists of a single-molecule magnet sandwiched between a ferromagnetic electrode and a normal metal electrode. Our numerical results demonstrate that the molecular magnetism orientation can be manipulated by magnetic fields to be parallel/antiparallel to the ferromagnetic electrode magnetization. Moreover, different magnetic configurations can be "read out" based on different resistance states or different spin polarization parameters in the current spectrum, even in the absence of a magnetic field. Such an external magnetic field-controlled resistance state switching effect is similar to that in traditional spin valve devices. The difference between the two systems is that one of the ferromagnetic layers in the original device has been replaced by a magnetic molecule. This proposed scheme provides the possibility of better control of the spin freedom of electrons in molecular electrical devices, with potential applications in future high-density nonvolatile memory devices. 参考文献 | 相关文章 | 计量指标

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Effect of TbF3 diffusion on the demagnetization behavior and domain evolution of sintered Nd-Fe-B magnets by electrophoretic deposition Xue-Jing Cao(曹学静), Shuai Guo(郭帅), Yu-Heng Xie(谢宇恒), Lei Jin(金磊), Guang-Fei Ding(丁广飞),Bo Zheng(郑波), Ren-Jie Chen(陈仁杰), and A-Ru Yan(闫阿儒) 2023 (9):  97503-097503.  doi: 10.1088/1674-1056/acaf2d 摘要 ( 166 )   HTML ( 1 )   PDF(1295KB) ( 72 )   We studied the magnetic properties and domain evolution of annealed and TbF3-diffused sintered Nd-Fe-B magnets using the electrophoretic deposition method. After TbF3 diffusion, the coercivity increased significantly by 9.9 kOe and microstructural analysis suggested that Tb favored the formation of the (Nd, Tb)2Fe14B shell phase in the outer region of the matrix grains. The first magnetization reversal and the dynamic successive domain propagation process were detected with a magneto-optical Kerr microscope. For the TbF3-diffused magnet, the magnetization reversal appeared at a larger applied field and the degree of simultaneous magnetization reversal decreased compared with an annealed magnet. During demagnetization after full magnetization, the occurrence of domain wall motion (DWM) in the reproduced multi-domain regions was observed by the step method. The maximum polarization change resulting from the reproduced DWM was inversely related to the coercivity. The increased coercivity for the diffused magnet was mainly attributed to the more difficult nucleation of the magnetic reversed region owing to the improved magneto-crystalline anisotropy field as a result of Tb diffusion. 参考文献 | 相关文章 | 计量指标

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Effect of CeO2 doping on the coercivity of 2:17 type SmCo magnets Xiao-Lei Gao(高晓磊), Zhuang Liu(刘壮), Guang-Qing Wang(王广庆), Chao-Qun Zhu(竺超群), Wen-Xin Cheng(程文鑫), Ming-Xiao Zhang(张明晓), Xin-Cai Liu(刘新才), Ren-Jie Chen(陈仁杰), and A-Ru Yan(闫阿儒) 2023 (9):  97504-097504.  doi: 10.1088/1674-1056/acaa24 摘要 ( 187 )   HTML ( 0 )   PDF(8642KB) ( 43 )   The effects of CeO2 doping on the magnetic properties and microstructure of 2:17 type SmCo magnets are studied. With the increase of CeO2 from 0 wt.% to 3 wt.%, the coercivity of the magnets increases from 22.22 kOe to over 29.37 kOe, which is an increase of more than 30%. When the doping content is lower than 1 wt.%, the remanence and magnetic energy product of the magnets remain almost constant. Both decrease sharply as the doping concentration further increases. After CeO2 doping, the oxide content in the magnet increases significantly and the Ce element is uniformly distributed in the magnet. Observing the magnetic domains reveals that doping with CeO2 can refine the magnetic domains and make the magnetic domain wall more stable, resulting in a significant increase in the coercivity of the magnets. 参考文献 | 相关文章 | 计量指标

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Impact of annealing temperature on the ferroelectric properties of W/Hf0.5Zr0.5O2/W capacitor Dao Wang(王岛), Yan Zhang(张岩), Yongbin Guo(郭永斌), Zhenzhen Shang(尚真真), Fangjian Fu(符方健), and Xubing Lu(陆旭兵) 2023 (9):  97701-097701.  doi: 10.1088/1674-1056/aca9c6 摘要 ( 161 )   HTML ( 0 )   PDF(1231KB) ( 50 )   Crystallization annealing is a crucial process for the formation of the ferroelectric phase in HfO2-based ferroelectric thin films. Here, we systematically investigate the impact of the annealing process, with temperature varied from 350 ℃ to 550 ℃, on the electricity, ferroelectricity and reliability of a Hf0.5Zr0.5O2 (HZO; 7.5 nm) film capacitor. It was found that HZO film annealed at a low temperature of 400 ℃ can effectively suppress the formation of the monoclinic phase and reduce the leakage current. HZO film annealed at 400 ℃ also exhibits better ferroelectric properties than those annealed at 350 ℃ and 550 ℃. Specifically, the 400 ℃-annealed HZO film shows an outstanding 2Pr value of 54.6 upmu C·cm-2 at ±3.0 MV·cm-1, which is relatively high compared with previously reported values for HZO film under the same electric field and annealing temperature. When the applied electric field increases to ±5.0 MV·cm-1, the 2Pr value can reach a maximum of 69.6 upmu C·cm-2. In addition, the HZO films annealed at 400 ℃ and 550 ℃ can endure up to bout 2.3×108 cycles under a cycling field of 2.0 MV·cm-1 before the occurrence of breakdown. In the 400 ℃-annealed HZO film, 72.1% of the initial polarization is maintained while only 44.9% is maintained in the 550 ℃-annealed HZO film. Our work demonstrates that HZO film with a low crystallization temperature (400 ℃) has quite a high ferroelectric polarization, which is of significant importance in applications in ferroelectric memory and negative capacitance transistors. 参考文献 | 相关文章 | 计量指标

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High-pressure and high-temperature sintering of pure cubic silicon carbide: A study on stress-strain and densification Jin-Xin Liu(刘金鑫), Fang Peng(彭放), Guo-Long Ma(马国龙), Wen-Jia Liang(梁文嘉), Rui-Qi He(何瑞琦), Shi-Xue Guan(管诗雪), Yue Tang(唐越), and Xiao-Jun Xiang(向晓君) 2023 (9):  98101-098101.  doi: 10.1088/1674-1056/aca6d4 摘要 ( 169 )   HTML ( 2 )   PDF(2357KB) ( 47 )   Silicon carbide (SiC) is a high-performance structural ceramic material with excellent comprehensive properties, and is unmatched by metals and other structural materials. In this paper, raw SiC powder with an average grain size of 5 upmu m was sintered by an isothermal-compression process at 5.0 GPa and 1500 ℃; the maximum hardness of the sintered samples was 31.3 GPa. Subsequently, scanning electron microscopy was used to observe the microscopic morphology of the recovered SiC samples treated in a temperature and extended pressure range of 0-1500 ℃ and 0-16.0 GPa, respectively. Defects and plastic deformation in the SiC grains were further analyzed by transmission electron microscopy. Further, high-pressure in situ synchrotron radiation x-ray diffraction was used to study the intergranular stress distribution and yield strength under non-hydrostatic compression. This study provides a new viewpoint for the sintering of pure phase micron-sized SiC particles. 参考文献 | 相关文章 | 计量指标

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Intercalation of hafnium oxide between epitaxially-grown monolayer graphene and Ir(111) substrate Yi Biao(表奕), Hong-Liang Lu(路红亮), Hao Peng(彭浩), Zhi-Peng Song(宋志朋), Hui Guo(郭辉), and Xiao Lin(林晓) 2023 (9):  98102-098102.  doi: 10.1088/1674-1056/accff4 摘要 ( 166 )   HTML ( 0 )   PDF(947KB) ( 123 )   Intercalation of insulating materials between epitaxial graphene and the metal substrates is highly demanded to restore the intrinsic properties of graphene, and thus essential for the graphene-based devices. Here we demonstrate a successful solution for the intercalation of hafnium oxide into the interface between full-layer graphene and Ir(111) substrate. We first intercalate hafnium atoms beneath the epitaxial graphene. The intercalation of the hafnium atoms leads to the variation of the graphene moiré superstructure periodicity, which is characterized by low-energy electron diffraction (LEED) and low-temperature scanning tunneling microscopy (LT-STM). Subsequently, we introduce oxygen into the interface, resulting in oxidization of the intercalated hafnium. STM and Raman's characterizations reveal that the intercalated hafnium oxide layer could effectively decouple the graphene from the metallic substrate, while the graphene maintains its high quality. Our work suggests a high-k dielectric layer has been successfully intercalated between high-quality epitaxial graphene and metal substrate, providing a platform for applications of large-scale, high-quality graphene for electronic devices. 参考文献 | 相关文章 | 计量指标

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High-temperature continuous-wave operation of 1310 nm InAs/GaAs quantum dot lasers Xiang-Bin Su(苏向斌), Fu-Hui Shao(邵福会), Hui-Ming Hao(郝慧明), Han-Qing Liu(刘汗青),Shu-Lun Li(李叔伦), De-Yan Dai(戴德炎), Xiang-Jun Shang(尚向军), Tian-Fang Wang(王天放),Yu Zhang(张宇), Cheng-Ao Yang(杨成奥), Ying-Qiang Xu(徐应强), Hai-Qiao Ni(倪海桥),Ying Ding(丁颖), and Zhi-Chuan Niu(牛智川) 2023 (9):  98103-098103.  doi: 10.1088/1674-1056/acb491 摘要 ( 210 )   HTML ( 3 )   PDF(1402KB) ( 96 )   Here we report 1.3 upmu m electrical injection lasers based on InAs/GaAs quantum dots (QDs) grown on a GaAs substrate, which can steadily work at 110 ℃ without visible degradation. The QD structure is designed by applying the Stranski-Krastanow growth mode in solid source molecular beam epitaxy. The density of InAs QDs in the active region is increased from 3.8×1010 cm-2 to 5.9×1010 cm-2. As regards laser performance, the maximum output power of devices with low-density QDs as the active region is 65 mW at room temperature, and that of devices with the high-density QDs is 103 mW. Meanwhile the output power of high-density devices is 131 mW under an injection current of 4 A at 110 ℃. 参考文献 | 相关文章 | 计量指标

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An artificial neural network potential for uranium metal at low pressures Maosheng Hao(郝茂生) and Pengfei Guan(管鹏飞) 2023 (9):  98401-098401.  doi: 10.1088/1674-1056/acd8a4 摘要 ( 185 )   HTML ( 4 )   PDF(1163KB) ( 122 )   Based on machine learning, the high-dimensional fitting of potential energy surfaces under the framework of first principles provides density-functional accuracy of atomic interaction potential for high-precision and large-scale simulation of alloy materials. In this paper, we obtained the high-dimensional neural network (NN) potential function of uranium metal by training a large amount of first-principles calculated data. The lattice constants of uranium metal with different crystal structures, the elastic constants, and the anisotropy of lattice expansion of alpha-uranium obtained based on this potential function are highly consistent with first-principles calculation or experimental data. In addition, the calculated formation energy of vacancies in alpha- and beta-uranium also matches the first-principles calculation. The calculated site of the most stable self-interstitial and its formation energy is in good agreement with the findings from density functional theory (DFT) calculations. These results show that our potential function can be used for further large-scale molecular dynamics simulation studies of uranium metal at low pressures, and provides the basis for further construction of potential model suitable for a wide range of pressures. 参考文献 | 相关文章 | 计量指标

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Analytical workload dependence of self-heating effect for SOI MOSFETs considering two-stage heating process Yi-Fan Li(李逸帆), Tao Ni(倪涛), Xiao-Jing Li(李晓静), Juan-Juan Wang(王娟娟), Lin-Chun Gao(高林春), Jian-Hui Bu(卜建辉), Duo-Li Li(李多力), Xiao-Wu Cai(蔡小五), Li-Da Xu(许立达), Xue-Qin Li(李雪勤), Run-Jian Wang(王润坚), Chuan-Bin Zeng(曾传滨), Bo Li(李博), Fa-Zhan Zhao(赵发展), Jia-Jun Luo(罗家俊), and Zheng-Sheng Han(韩郑生) 2023 (9):  98501-098501.  doi: 10.1088/1674-1056/acc8c0 摘要 ( 172 )   HTML ( 0 )   PDF(2406KB) ( 29 )   Dynamic self-heating effect (SHE) of silicon-on-insulator (SOI) MOSFET is comprehensively evaluated by ultrafast pulsed I-V measurement in this work. It is found for the first time that the SHE complete heating response and cooling response of SOI MOSFETs are conjugated, with two-stage curves shown. We establish the effective thermal transient response model with stage superposition corresponding to the heating process. The systematic study of SHE dependence on workload shows that frequency and duty cycle have more significant effect on SHE in first-stage heating process than in the second stage. In the first-stage heating process, the peak lattice temperature and current oscillation amplitude decrease by more than 25 K and 4% with frequency increasing to 10 MHz, and when duty cycle is reduced to 25%, the peak lattice temperature drops to 306 K and current oscillation amplitude decreases to 0.77%. Finally, the investigation of two-stage (heating and cooling) process provides a guideline for the unified optimization of dynamic SHE in terms of workload. As the operating frequency is raised to GHz, the peak temperature depends on duty cycle, and self-heating oscillation is completely suppressed. 参考文献 | 相关文章 | 计量指标

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NiO/β-Ga2O3 heterojunction diodes with ultra-low leakage current below 10-10 A and high thermostability Yi Huang(黄义), Wen Yang(杨稳), Qi Wang(王琦), Sheng Gao(高升), Wei-Zhong Chen(陈伟中), Xiao-Sheng Tang(唐孝生), Hong-Sheng Zhang(张红升), and Bin Liu(刘斌) 2023 (9):  98502-098502.  doi: 10.1088/1674-1056/aca4be 摘要 ( 170 )   HTML ( 0 )   PDF(1197KB) ( 156 )   The 10 nm p-NiO thin film is prepared by thermal oxidation of Ni on β-Ga2O3 to form NiO/β-Ga2O3 p-n heterojunction diodes (HJDs). The NiO/β-Ga2O3 HJDs exhibit excellent electrostatic properties, with a high breakdown voltage of 465 V, a specific on-resistance (Ron,sp) of 3.39 mΩ ·cm2, and a turn-on voltage (Von) of 1.85 V, yielding a static Baliga's figure of merit (FOM) of 256 MW/cm2. Also, the HJDs have a low turn-on voltage, which reduces conduction loss dramatically, and a rectification ratio of up to 108. Meanwhile, the HJDs' reverse leakage current is essentially unaffected at temperatures below 170 ℃, and their leakage level may be controlled below 10-10 A. This indicates that p-NiO/β-Ga2O3 HJDs with good thermal stability and high-temperature operating ability can be a good option for high-performance β-Ga2O3 power devices. 参考文献 | 相关文章 | 计量指标

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Temperature dependence of single-event transients in SiGe heterojunction bipolar transistors for cryogenic applications Xiaoyu Pan(潘霄宇), Hongxia Guo(郭红霞), Yahui Feng(冯亚辉), Yinong Liu(刘以农), Jinxin Zhang(张晋新), Jun Fu(付军), and Guofang Yu(喻国芳) 2023 (9):  98503-098503.  doi: 10.1088/1674-1056/acaa28 摘要 ( 177 )   HTML ( 0 )   PDF(6512KB) ( 96 )   We experimentally demonstrate that the dominant mechanism of single-event transients in silicon-germanium heterojunction bipolar transistors (SiGe HBTs) can change with decreasing temperature from +20 ℃ to -180 ℃. This is accomplished by using a new well-designed cryogenic experimental system suitable for a pulsed-laser platform. Firstly, when the temperature drops from +20 ℃ to -140 ℃, the increased carrier mobility drives a slight increase in transient amplitude. However, as the temperature decreases further below -140 ℃, the carrier freeze-out brings about an inflection point, which means the transient amplitude will decrease at cryogenic temperatures. To better understand this result, we analytically calculate the ionization rates of various dopants at different temperatures based on Altermatt's new incomplete ionization model. The parasitic resistivities with temperature on the charge-collection pathway are extracted by a two-dimensional (2D) TCAD process simulation. In addition, we investigate the impact of temperature on the novel electron-injection process from emitter to base under different bias conditions. The increase of the emitter-base junction's barrier height at low temperatures could suppress this electron-injection phenomenon. We have also optimized the built-in voltage equations of a high current compact model (HICUM) by introducing the impact of incomplete ionization. The present results and methods could provide a new reference for effective evaluation of single-event effects in bipolar transistors and circuits at cryogenic temperatures, and could provide a new evidence of the potential of SiGe technology in applications in extreme cryogenic environments. 参考文献 | 相关文章 | 计量指标

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Ultra-high photoresponsive photodetector based on ReS2/SnS2 heterostructure Binghui Wang(王冰辉), Yanhui Xing(邢艳辉), Shengyuan Dong(董晟园), Jiahao Li(李嘉豪), Jun Han(韩军), Huayao Tu(涂华垚), Ting Lei(雷挺), Wenxin He(贺雯馨), Baoshun Zhang(张宝顺), and Zhongming Zeng(曾中明) 2023 (9):  98504-098504.  doi: 10.1088/1674-1056/acd9c0 摘要 ( 178 )   HTML ( 5 )   PDF(1906KB) ( 90 )   Photodetectors based on two-dimensional materials have attracted much attention because of their unique structure and outstanding performance. The response speed of single ReS2 photodetector is slow exceptionally, the heterostructure could improves the response speed of ReS2-based photodetector, but the photodetectors responsivity is reduced greatly, which restricts the development of ReS2. In this paper, a vertically structured ReS2 /SnS2 van der Waals heterostructure photodetectors is prepared, using ReS2 as the transport layer and SnS2 as the light absorbing layer to regulate the channel current. The device has an ultra-high photoconductive gain of 1010, which exhibits an ultra-high responsivity of 4706 A/W under 365-nm illumination and response speed in seconds, and has an ultra-high external quantum efficiency of 1.602×106% and a high detectivity of 5.29×1012 jones. The study for ReS2-based photodetector displays great potential for developing future optoelectronic devices. 参考文献 | 相关文章 | 计量指标

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Novel layout design of 4H-SiC merged PiN Schottky diodes leading to improved surge robustness Jia-Hao Chen(陈嘉豪), Ying Wang(王颖), Xin-Xing Fei(费新星), Meng-Tian Bao(包梦恬), and Fei Cao(曹菲) 2023 (9):  98505-098505.  doi: 10.1088/1674-1056/acad6b 摘要 ( 170 )   HTML ( 2 )   PDF(1681KB) ( 50 )   A method to improve the surge current capability of silicon carbide (SiC) merged PiN Schottky (MPS) diodes is presented and investigated via three-dimensional electro-thermal simulations. When compared with a conventional MPS diode, the proposed structure has a more uniform current distribution during bipolar conduction due to the help of the continuous P+ surface, which can avoid the formation of local hotspots during the surge process. The Silvaco simulation results show that the proposed structure has a 20.29% higher surge capability and a 15.06% higher surge energy compared with a conventional MPS diode. The bipolar on-state voltage of the proposed structure is 4.69 V, which is 56.29% lower than that of a conventional MPS diode, enabling the device to enter the bipolar mode earlier during the surge process. Furthermore, the proposed structure can suppress the occurrence of 'snapback' phenomena when switching from the unipolar to the bipolar operation mode. In addition, an analysis of the surge process of MPS diodes is carried out in detail. 参考文献 | 相关文章 | 计量指标

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High performance solar-blind deep ultraviolet photodetectors via β-phase (In0.09Ga0.91)2O3 single crystalline film Bicheng Wang(王必成), Ziying Tang(汤梓荧), Huying Zheng(郑湖颖), Lisheng Wang(王立胜), Yaqi Wang(王亚琪), Runchen Wang(王润晨), Zhiren Qiu(丘志仁), and Hai Zhu(朱海) 2023 (9):  98508-098508.  doi: 10.1088/1674-1056/acd3e4 摘要 ( 216 )   HTML ( 4 )   PDF(2227KB) ( 295 )   We successfully fabricate a high performance β-phase (In0.09Ga0.91)2O3 single-crystalline film deep ultraviolet (DUV) solar-blind photodetector. The 2-inches high crystalline quality film is hetero-grown on the sapphire substrates using the plasma-assisted molecular beam epitaxy (PA-MBE). The smooth InGaO single crystalline film is used to construct the solar-blind DUV detector, which utilized an interdigitated Ti/Au electrode with a metal-semiconductor-metal structure. The device exhibits a low dark current of 40 pA (0 V), while its UV photon responsivity exceeds 450 A/W (50 V) at the peak wavelength of 232 nm with illumination intensity of 0.21 mW/cm2 and the UV/VIS rejection ratio (R232 nm/R380 nm) exceeds 4×104. Furthermore, the devices demonstrate ultrafast transient characteristics for DUV signals, with fast-rising and fast-falling times of 80 ns and 420 ns, respectively. This excellent temporal dynamic behavior can be attributed to indium doping can adjust the electronic structure of Ga2O3 alloys to enhance the performance of InGaO solar-blind detectors. Additionally, a two-dimensional DUV scanning image is captured using the InGaO photodetector as a sensor in an imaging system. Our results pave the way for future applications of two-dimensional array DUV photodetectors based on the large-scale InGaO heteroepitaxially grown alloy wide bandgap semiconductor films. 参考文献 | 相关文章 | 计量指标

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Free running period affected by network structures of suprachiasmatic nucleus neurons exposed to constant light Jian Zhou(周建), Changgui Gu(顾长贵), Yuxuan Song(宋雨轩), and Yan Xu(许艳) 2023 (9):  98701-098701.  doi: 10.1088/1674-1056/acd7ce 摘要 ( 182 )   HTML ( 0 )   PDF(1339KB) ( 107 )   Exposed to the natural light-dark cycle, 24 h rhythms exist in behavioral and physiological processes of living beings. Interestingly, under constant darkness or constant light, living beings can maintain a robust endogenous rhythm with a free running period (FRP) close to 24 h. In mammals, the circadian rhythm is coordinated by a master clock located in the suprachiasmatic nucleus (SCN) of the brain, which is composed of about twenty thousand self-oscillating neurons. These SCN neurons form a heterogenous network to output a robust rhythm. Thus far, the exact network topology of the SCN neurons is unknown. In this article, we examine the effect of the SCN network structure on the FRP when exposed to constant light by a Poincaré model. Four typical network structures are considered, including a nearest-neighbor coupled network, a Newman-Watts small world network, an Erdös-Rényi random network and a Barabási-Albert (BA) scale free network. The results show that the FRP is longest in the BA network, because the BA network is characterized by the most heterogeneous structure among these four types of networks. These findings are not affected by the average node degree of the SCN network or the value of relaxation rate of the SCN neuronal oscillators. Our findings contribute to the understanding of how the network structure of the SCN neurons influences the FRP. 参考文献 | 相关文章 | 计量指标

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Important edge identification in complex networks based on local and global features Jia-Hui Song(宋家辉) 2023 (9):  98901-098901.  doi: 10.1088/1674-1056/aca6d8 摘要 ( 186 )   HTML ( 0 )   PDF(4833KB) ( 74 )   Identifying important nodes and edges in complex networks has always been a popular research topic in network science and also has important implications for the protection of real-world complex systems. Finding the critical structures in a system allows us to protect the system from attacks or failures with minimal cost. To date, the problem of identifying critical nodes in networks has been widely studied by many scholars, and the theory is becoming increasingly mature. However, there is relatively little research related to edges. In fact, critical edges play an important role in maintaining the basic functions of the network and keeping the integrity of the structure. Sometimes protecting critical edges is less costly and more flexible in operation than just focusing on nodes. Considering the integrity of the network topology and the propagation dynamics on it, this paper proposes a centrality measure based on the number of high-order structural overlaps in the first and second-order neighborhoods of edges. The effectiveness of the metric is verified by the infection-susceptibility (SI) model, the robustness index R, and the number of connected branches θ. A comparison is made with three currently popular edge importance metrics from two synthetic and four real networks. The simulation results show that the method outperforms existing methods in identifying critical edges that have a significant impact on both network connectivity and propagation dynamics. At the same time, the near-linear time complexity can be applied to large-scale networks. 参考文献 | 相关文章 | 计量指标

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Percolation transitions in edge-coupled interdependent networks with directed dependency links Yan-Li Gao(高彦丽), Hai-Bo Yu(于海波), Jie Zhou(周杰), Yin-Zuo Zhou(周银座), and Shi-Ming Chen(陈世明) 2023 (9):  98902-098902.  doi: 10.1088/1674-1056/acd685 摘要 ( 219 )   HTML ( 0 )   PDF(1320KB) ( 49 )   We propose a model of edge-coupled interdependent networks with directed dependency links (EINDDLs) and develop the theoretical analysis framework of this model based on the self-consistent probabilities method. The phase transition behaviors and parameter thresholds of this model under random attacks are analyzed theoretically on both random regular (RR) networks and Erdös-Rényi (ER) networks, and computer simulations are performed to verify the results. In this EINDDL model, a fraction β of connectivity links within network B depends on network A and a fraction (1-β) of connectivity links within network A depends on network B. It is found that randomly removing a fraction (1-p) of connectivity links in network A at the initial state, network A exhibits different types of phase transitions (first order, second order and hybrid). Network B is rarely affected by cascading failure when β is small, and network B will gradually converge from the first-order to the second-order phase transition as β increases. We present the critical values of β for the phase change process of networks A and B, and give the critical values of p and β for network B at the critical point of collapse. Furthermore, a cascading prevention strategy is proposed. The findings are of great significance for understanding the robustness of EINDDLs. 参考文献 | 相关文章 | 计量指标

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Self-similarity of complex networks under centrality-based node removal strategy Dan Chen(陈单), Defu Cai(蔡德福), and Housheng Su(苏厚胜) 2023 (9):  98903-098903.  doi: 10.1088/1674-1056/acd3e2 摘要 ( 208 )   HTML ( 0 )   PDF(1525KB) ( 159 )   Real-world networks exhibit complex topological interactions that pose a significant computational challenge to analyses of such networks. Due to limited resources, there is an urgent need to develop dimensionality reduction techniques that can significantly reduce the structural complexity of initial large-scale networks. In this paper, we propose a subgraph extraction method based on the node centrality measure to reduce the size of the initial network topology. Specifically, nodes with smaller centrality value are removed from the initial network to obtain a subgraph with a smaller size. Our results demonstrate that various real-world networks, including power grids, technology, transportation, biology, social, and language networks, exhibit self-similarity behavior during the reduction process. The present results reveal the self-similarity and scale invariance of real-world networks from a different perspective and also provide an effective guide for simplifying the topology of large-scale networks. 参考文献 | 补充材料 | 相关文章 | 计量指标

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Identifying multiple influential spreaders in complex networks based on spectral graph theory Dong-Xu Cui(崔东旭), Jia-Lin He(何嘉林), Zi-Fei Xiao(肖子飞), and Wei-Ping Ren(任卫平) 2023 (9):  98904-098904.  doi: 10.1088/1674-1056/acac0b 摘要 ( 191 )   HTML ( 4 )   PDF(1097KB) ( 127 )   One of the hot research topics in propagation dynamics is identifying a set of critical nodes that can influence maximization in a complex network. The importance and dispersion of critical nodes among them are both vital factors that can influence maximization. We therefore propose a multiple influential spreaders identification algorithm based on spectral graph theory. This algorithm first quantifies the role played by the local structure of nodes in the propagation process, then classifies the nodes based on the eigenvectors of the Laplace matrix, and finally selects a set of critical nodes by the constraint that nodes in the same class are not adjacent to each other while different classes of nodes can be adjacent to each other. Experimental results on real and synthetic networks show that our algorithm outperforms the state-of-the-art and classical algorithms in the SIR model. 参考文献 | 相关文章 | 计量指标

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Robustness of community networks against cascading failures with heterogeneous redistribution strategies Bo Song(宋波), Hui-Ming Wu(吴惠明), Yu-Rong Song(宋玉蓉), Guo-Ping Jiang(蒋国平),Ling-Ling Xia(夏玲玲), and Xu Wang(王旭) 2023 (9):  98905-098905.  doi: 10.1088/1674-1056/acd9c3 摘要 ( 189 )   HTML ( 3 )   PDF(887KB) ( 153 )   Network robustness is one of the core contents of complex network security research. This paper focuses on the robustness of community networks with respect to cascading failures, considering the nodes influence and community heterogeneity. A novel node influence ranking method, community-based Clustering-LeaderRank (CCL) algorithm, is first proposed to identify influential nodes in community networks. Simulation results show that the CCL method can effectively identify the influence of nodes. Based on node influence, a new cascading failure model with heterogeneous redistribution strategy is proposed to describe and analyze node fault propagation in community networks. Analytical and numerical simulation results on cascading failure show that the community attribute has an important influence on the cascading failure process. The network robustness against cascading failures increases when the load is more distributed to neighbors of the same community instead of different communities. When the initial load distribution and the load redistribution strategy based on the node influence are the same, the network shows better robustness against node failure. 参考文献 | 相关文章 | 计量指标