Chinese Physics B最新文献

{"title":"Transport properties of Hall-type quantum states in disordered bismuthene","authors":"Jiaojiao Zhou, Jiangying Yu, Shuguang Cheng, Hua Jiang","doi":"10.1088/1674-1056/ad2605","DOIUrl":"https://doi.org/10.1088/1674-1056/ad2605","url":null,"abstract":"Bismuthene, an inherently hexagonal structure characterized by a huge bulk gap, offers a versatile platform for investigating the electronic transport of various topological quantum states. Using nonequilibrium Green’s function method and Landauer–Büttiker formula, we thoroughly investigate the transport properties of various Hall-type quantum states, including quantum spin Hall (QSH) edge states, quantum valley Hall kink (QVHK) states, and quantum spin–valley Hall kink (QSVHK) states, in the presence of various disorders. Based on the exotic transport features, a spin–valley filter, capable of generating a highly spin- and valley-polarized current, is proposed. The valley index and the spin index of the filtered QSVHK state are determined by the staggered potential and the intrinsic spin–orbit coupling, respectively. The efficiency of the spin–valley filter is supported by the spacial current distribution, the valley-resolved conductance, and the spin-resolved conductance. Compared with a sandwich structure for QSVHK, our proposed spin–valley filter can work with a much smaller size and is more accessible in the experiment.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"25 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140614143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elliptically polarized high-order harmonic generation of Ar atom in an intense laser field","authors":"Jie Hu, Yi-Chen Wang, Qiu-Shuang Jing, Wei Jiang, Ge-Wen Wang, Yi-Wen Zhao, Bo Xiao, Hong-Jing Liang, Ri Ma","doi":"10.1088/1674-1056/ad2604","DOIUrl":"https://doi.org/10.1088/1674-1056/ad2604","url":null,"abstract":"High-order harmonic generation (HHG) of Ar atom in an elliptically polarized intense laser field is experimentally investigated in this work. Interestingly, the anomalous ellipticity dependence on the laser ellipticity (<italic toggle=\"yes\">ε</italic>) in the lower-order harmonics is observed, specifically in the 13rd-order, which displays a maximal harmonic intensity at <italic toggle=\"yes\">ε</italic> ≈ 0.1, rather than at <italic toggle=\"yes\">ε</italic> = 0 as expected. This contradicts the general trend of harmonic yield, which typically decreases with the increase of laser ellipticity. In this study, we attribute this phenomenon to the disruption of the symmetry of the wave function by the Coulomb effect, leading to the generation of a harmonic with high ellipticity. This finding provides valuable insights into the behavior of elliptically polarized harmonics and opens up a potential way for exploring new applications in ultrafast spectroscopy and light–matter interactions.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"19 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140804657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergent topological ordered phase for the Ising-XY model revealed by cluster-updating Monte Carlo method","authors":"Heyang Ma, Wanzhou Zhang, Yanting Tian, Chengxiang Ding, Youjin Deng","doi":"10.1088/1674-1056/ad1d4d","DOIUrl":"https://doi.org/10.1088/1674-1056/ad1d4d","url":null,"abstract":"The two-component cold atom systems with anisotropic hopping amplitudes can be phenomenologically described by a two-dimensional Ising-<italic toggle=\"yes\">XY</italic> coupled model with spatial anisotropy. At low temperatures, theoretical predictions [<italic toggle=\"yes\">Phys. Rev. A</italic>\u0000<bold>72</bold> 053604 (2005)] and [arXiv: 0706.1609] indicate the existence of a topological ordered phase characterized by Ising and <italic toggle=\"yes\">XY</italic> disorder but with 2<italic toggle=\"yes\">XY</italic> ordering. However, due to ergodic difficulties faced by Monte Carlo methods at low temperatures, this topological phase has not been numerically explored. We propose a linear cluster updating Monte Carlo method, which flips spins without rejection in the anisotropy limit but does not change the energy. Using this scheme and conventional Monte Carlo methods, we succeed in revealing the nature of topological phases with half-vortices and domain walls. In the constructed global phase diagram, Ising and <italic toggle=\"yes\">XY</italic>-type transitions are very close to each other and differ significantly from the schematic phase diagram reported earlier. We also propose and explore a wide range of quantities, including magnetism, superfluidity, specific heat, susceptibility, and even percolation susceptibility, and obtain consistent and reliable results. Furthermore, we observed first-order transitions characterized by common intersection points in magnetizations for different system sizes, as opposed to the conventional phase transition where Binder cumulants of various sizes share common intersections. The critical exponents of different types of phase transitions are reasonably fitted. The results are useful to help cold atom experiments explore the half-vortex topological phase.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"53 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140608965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Symmetry transformation of nonlinear optical current of tilted Weyl nodes and application to ferromagnetic MnBi2Te4","authors":"Zhuo-Cheng Lu, Ji Feng","doi":"10.1088/1674-1056/ad2bfb","DOIUrl":"https://doi.org/10.1088/1674-1056/ad2bfb","url":null,"abstract":"A Weyl node is characterized by its chirality and tilt. We develop a theory of how <italic toggle=\"yes\">n</italic>th-order nonlinear optical conductivity behaves under transformations of anisotropic tensor and tilt, which clarifies how chirality-dependent and -independent parts of optical conductivity transform under the reversal of tilt and chirality. Built on this theory, we propose ferromagnetic MnBi₂Te₄ as a magnetoelectrically regulated, terahertz optical device, by magnetoelectrically switching the chirality-dependent and -independent DC photocurrents. These results are useful for creating nonlinear optical devices based on the topological Weyl semimetals.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"301 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140608871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computing large deviation prefactors of stochastic dynamical systems based on machine learning","authors":"Yang Li, Shenglan Yuan, Linghongzhi Lu, Xianbin Liu","doi":"10.1088/1674-1056/ad12a8","DOIUrl":"https://doi.org/10.1088/1674-1056/ad12a8","url":null,"abstract":"We present a large deviation theory that characterizes the exponential estimate for rare events in stochastic dynamical systems in the limit of weak noise. We aim to consider a next-to-leading-order approximation for more accurate calculation of the mean exit time by computing large deviation prefactors with the aid of machine learning. More specifically, we design a neural network framework to compute quasipotential, most probable paths and prefactors based on the orthogonal decomposition of a vector field. We corroborate the higher effectiveness and accuracy of our algorithm with two toy models. Numerical experiments demonstrate its powerful functionality in exploring the internal mechanism of rare events triggered by weak random fluctuations.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"128 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140614236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tunable superconducting resonators via on-chip control of local magnetic field","authors":"Chen-Guang Wang, Wen-Cheng Yue, Xuecou Tu, Tianyuan Chi, Tingting Guo, Yang-Yang Lyu, Sining Dong, Chunhai Cao, Labao Zhang, Xiaoqing Jia, Guozhu Sun, Lin Kang, Jian Chen, Yong-Lei Wang, Huabing Wang, Peiheng Wu","doi":"10.1088/1674-1056/ad2f21","DOIUrl":"https://doi.org/10.1088/1674-1056/ad2f21","url":null,"abstract":"Superconducting microwave resonators play a pivotal role in superconducting quantum circuits. The ability to fine-tune their resonant frequencies provides enhanced control and flexibility. Here, we introduce a frequency-tunable superconducting coplanar waveguide resonator. By applying electrical currents through specifically designed ground wires, we achieve the generation and control of a localized magnetic field on the central line of the resonator, enabling continuous tuning of its resonant frequency. We demonstrate a frequency tuning range of 54.85 MHz in a 6.21-GHz resonator. This integrated and tunable resonator holds great potential as a dynamically tunable filter and as a key component of communication buses and memory elements in superconducting quantum computing.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140929136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quafu-Qcover: Explore combinatorial optimization problems on cloud-based quantum computers","authors":"Hong-Ze Xu, Wei-Feng Zhuang, Zheng-An Wang, Kai-Xuan Huang, Yun-Hao Shi, Wei-Guo Ma, Tian-Ming Li, Chi-Tong Chen, Kai Xu, Yu-Long Feng, Pei Liu, Mo Chen, Shang-Shu Li, Zhi-Peng Yang, Chen Qian, Yu-Xin Jin, Yun-Heng Ma, Xiao Xiao, Peng Qian, Yanwu Gu, Xu-Dan Chai, Ya-Nan Pu, Yi-Peng Zhang, Shi-Jie Wei, Jin-Feng Zeng, Hang Li, Gui-Lu Long, Yirong Jin, Haifeng Yu, Heng Fan, Dong E. Liu, Meng-Jun Hu","doi":"10.1088/1674-1056/ad18ab","DOIUrl":"https://doi.org/10.1088/1674-1056/ad18ab","url":null,"abstract":"We introduce Quafu-Qcover, an open-source cloud-based software package developed for solving combinatorial optimization problems using quantum simulators and hardware backends. Quafu-Qcover provides a standardized and comprehensive workflow that utilizes the quantum approximate optimization algorithm (QAOA). It facilitates the automatic conversion of the original problem into a quadratic unconstrained binary optimization (QUBO) model and its corresponding Ising model, which can be subsequently transformed into a weight graph. The core of Qcover relies on a graph decomposition-based classical algorithm, which efficiently derives the optimal parameters for the shallow QAOA circuit. Quafu-Qcover incorporates a dedicated compiler capable of translating QAOA circuits into physical quantum circuits that can be executed on Quafu cloud quantum computers. Compared to a general-purpose compiler, our compiler demonstrates the ability to generate shorter circuit depths, while also exhibiting superior speed performance. Additionally, the Qcover compiler has the capability to dynamically create a library of qubits coupling substructures in real-time, utilizing the most recent calibration data from the superconducting quantum devices. This ensures that computational tasks can be assigned to connected physical qubits with the highest fidelity. The Quafu-Qcover allows us to retrieve quantum computing sampling results using a task ID at any time, enabling asynchronous processing. Moreover, it incorporates modules for results preprocessing and visualization, facilitating an intuitive display of solutions for combinatorial optimization problems. We hope that Quafu-Qcover can serve as an instructive illustration for how to explore application problems on the Quafu cloud quantum computers.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"39 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140806801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Localization effect in single crystal of RuAs2","authors":"Zhe-Kai Yi, Qi Liu, Shuang-Kui Guang, Sheng Xu, Xiao-Yu Yue, Hui Liang, Na Li, Ying Zhou, Dan-Dan Wu, Yan Sun, Qiu-Ju Li, Peng Cheng, Tian-Long Xia, Xue-Feng Sun, Yi-Yan Wang","doi":"10.1088/1674-1056/ad23d9","DOIUrl":"https://doi.org/10.1088/1674-1056/ad23d9","url":null,"abstract":"We report the magnetotransport and thermal properties of RuAs₂ single crystal. RuAs₂ exhibits semiconductor behavior and localization effect. The crossover from normal state to diffusive transport in the weak localization (WL) state and then to variable range hopping (VRH) transport in the strong localization state has been observed. The transitions can be reflected in the measurement of resistivity and Seebeck coefficient. Negative magnetoresistance (NMR) emerges with the appearance of localization effect and is gradually suppressed in high magnetic field. The temperature dependent phase coherence length extracted from the fittings of NMR also indicates the transition from WL to VRH. The measurement of Hall effect reveals an anomaly of temperature dependent carrier concentration caused by localization effect. Our findings show that RuAs₂ is a suitable platform to study the localized state.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"22 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140311823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Image segmentation of exfoliated two-dimensional materials by generative adversarial network-based data augmentation","authors":"Xiaoyu Cheng, Chenxue Xie, Yulun Liu, Ruixue Bai, Nanhai Xiao, Yanbo Ren, Xilin Zhang, Hui Ma, Chongyun Jiang","doi":"10.1088/1674-1056/ad23d8","DOIUrl":"https://doi.org/10.1088/1674-1056/ad23d8","url":null,"abstract":"Mechanically cleaved two-dimensional materials are random in size and thickness. Recognizing atomically thin flakes by human experts is inefficient and unsuitable for scalable production. Deep learning algorithms have been adopted as an alternative, nevertheless a major challenge is a lack of sufficient actual training images. Here we report the generation of synthetic two-dimensional materials images using StyleGAN3 to complement the dataset. DeepLabv3Plus network is trained with the synthetic images which reduces overfitting and improves recognition accuracy to over 90%. A semi-supervisory technique for labeling images is introduced to reduce manual efforts. The sharper edges recognized by this method facilitate material stacking with precise edge alignment, which benefits exploring novel properties of layered-material devices that crucially depend on the interlayer twist-angle. This feasible and efficient method allows for the rapid and high-quality manufacturing of atomically thin materials and devices.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"28 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140311940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"BaTiO3/p-GaN/Au self-driven UV photodetector with bipolar photocurrent controlled by ferroelectric polarization","authors":"Wushuang Han, Kewei Liu, Jialin Yang, Yongxue Zhu, Zhen Cheng, Xing Chen, Binghui Li, Lei Liu, Dezhen Shen","doi":"10.1088/1674-1056/ad2607","DOIUrl":"https://doi.org/10.1088/1674-1056/ad2607","url":null,"abstract":"Ferroelectric materials are promising candidates for ultraviolet photodetectors due to their ferroelectric effect. In this work, a BaTiO₃/p-GaN/Au hybrid heterojunction–Schottky self-driven ultraviolet photodetector was fabricated with excellent bipolar photoresponse property. At 0 V bias, the direction of the photocurrent can be switched by flipping the depolarization field of BaTiO₃, which allows the performance of photodetectors to be controlled by the ferroelectric effect. Meanwhile, a relatively large responsivity and a fast response speed can be also observed. In particular, when the depolarization field of BaTiO₃ is in the same direction of the built-in electric field of the Au/p-GaN Schottky junction (up polarized state), the photodetector exhibits a high responsivity of 18 mA/W at 360 nm, and a fast response speed of &lt; 40 ms at 0 V. These findings pave a new way for the preparation of high-performance photodetectors with bipolar photocurrents.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"39 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140560702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}