Pub Date : 2024-05-01DOI: 10.1088/1674-1056/ad2f20
Ke Zhang, Lan-Lan Li, Hong-Yi Fan
To conveniently calculate the Wigner function of the optical cumulant operator and its dissipation evolution in a thermal environment, in this paper, the thermo-entangled state representation is introduced to derive the general evolution formula of the Wigner function, and its relation to Weyl correspondence is also discussed. The method of integration within the ordered product of operators is essential to our discussion.
{"title":"Wigner function of optical cumulant operator and its dissipation in thermo-entangled state representation","authors":"Ke Zhang, Lan-Lan Li, Hong-Yi Fan","doi":"10.1088/1674-1056/ad2f20","DOIUrl":"https://doi.org/10.1088/1674-1056/ad2f20","url":null,"abstract":"To conveniently calculate the Wigner function of the optical cumulant operator and its dissipation evolution in a thermal environment, in this paper, the thermo-entangled state representation is introduced to derive the general evolution formula of the Wigner function, and its relation to Weyl correspondence is also discussed. The method of integration within the ordered product of operators is essential to our discussion.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"5 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141510316","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}
Pub Date : 2024-05-01DOI: 10.1088/1674-1056/ad2a6f
Qing Liu, Jin-Zhan Chen, He Wang, Jie Zhang, Wei-Min Ruan, Guo-Zhu Wu, Shun-Yuan Zheng, Jing-Ting Luo, Zhen-Fei Song
The strength of microwave (MW) electric field can be observed with high precision by using the standard electromagnetically induced transparency and Aulter–Towns (EIT-AT) technique, when its frequency is resonant or nearly-resonant with the Rydberg transition frequency. As the detuning of MW field increases, one of the transmission peaks (single peak) is easier to measure due to its increased amplitude. It can be found that the central symmetry point of the two transmission peaks f1/2 is only related to the detuning of MW field ΔMW and central symmetry point f0 of resonant MW field, satisfying the relation f1/2 = ΔMW/2 + f0. Thus, we demonstrate a single transmission peak method that the MW E-field can be determined by interval between the position of single peak and f1/2. We use this method to measure continuous frequencies in a band from −200 MHz to 200 MHz of the MW field. The experimental results and theoretical analysis are presented to describe the effectiveness of this method. For 50 MHz < ΔMW < 200 MHz, this method solves the problem that the AT splitting cannot be measured by using the standard EIT-AT techniques or multiple atomic-level Rydberg atom schemes.
{"title":"Extending microwave-frequency electric-field detection through single transmission peak method","authors":"Qing Liu, Jin-Zhan Chen, He Wang, Jie Zhang, Wei-Min Ruan, Guo-Zhu Wu, Shun-Yuan Zheng, Jing-Ting Luo, Zhen-Fei Song","doi":"10.1088/1674-1056/ad2a6f","DOIUrl":"https://doi.org/10.1088/1674-1056/ad2a6f","url":null,"abstract":"The strength of microwave (MW) electric field can be observed with high precision by using the standard electromagnetically induced transparency and Aulter–Towns (EIT-AT) technique, when its frequency is resonant or nearly-resonant with the Rydberg transition frequency. As the detuning of MW field increases, one of the transmission peaks (single peak) is easier to measure due to its increased amplitude. It can be found that the central symmetry point of the two transmission peaks <italic toggle=\"yes\">f</italic>\u0000<sub>1/2</sub> is only related to the detuning of MW field <italic toggle=\"yes\">Δ</italic>\u0000<sub>MW</sub> and central symmetry point <italic toggle=\"yes\">f</italic>\u0000<sub>0</sub> of resonant MW field, satisfying the relation <italic toggle=\"yes\">f</italic>\u0000<sub>1/2</sub> = <italic toggle=\"yes\">Δ</italic>\u0000<sub>MW</sub>/2 + <italic toggle=\"yes\">f</italic>\u0000<sub>0</sub>. Thus, we demonstrate a single transmission peak method that the MW E-field can be determined by interval between the position of single peak and <italic toggle=\"yes\">f</italic>\u0000<sub>1/2</sub>. We use this method to measure continuous frequencies in a band from −200 MHz to 200 MHz of the MW field. The experimental results and theoretical analysis are presented to describe the effectiveness of this method. For 50 MHz < <italic toggle=\"yes\">Δ</italic>\u0000<sub>MW</sub> < 200 MHz, this method solves the problem that the AT splitting cannot be measured by using the standard EIT-AT techniques or multiple atomic-level Rydberg atom schemes.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"44 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189719","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}
Pub Date : 2024-05-01DOI: 10.1088/1674-1056/ad2606
Pengzhao Wang, Lijie Qian, Zhenrong Sun, Yan Yang
Electron dynamics during non-sequential double ionization (NSDI) is one of the most attractive areas of research in the field of laser–atom or laser–molecule interaction. Based on the classic two-dimensional model, we study the process of NSDI of argon atoms driven by a few-cycle orthogonal two-color laser field composed of 800 nm and 400 nm laser pulses. By changing the relative phase of the two laser pulses, a localized enhancement of NSDI yield is observed at 0.5π and 1.5π, which could be attributed to a rapid and substantial increase in the number of electrons returning to the parent ion within extremely short time intervals at these specific phases. Through the analysis of the electron–electron momentum correlations within different time windows of NSDI events and the angular distributions of emitted electrons in different channels, we observe a more pronounced electron–electron correlation phenomenon in the recollision-induced ionization (RII) channel. This is attributed to the shorter delay time in the RII channel.
{"title":"Manipulating the electron dynamics in the non-sequential double ionization process of Ar atoms by an orthogonal two-color laser field","authors":"Pengzhao Wang, Lijie Qian, Zhenrong Sun, Yan Yang","doi":"10.1088/1674-1056/ad2606","DOIUrl":"https://doi.org/10.1088/1674-1056/ad2606","url":null,"abstract":"Electron dynamics during non-sequential double ionization (NSDI) is one of the most attractive areas of research in the field of laser–atom or laser–molecule interaction. Based on the classic two-dimensional model, we study the process of NSDI of argon atoms driven by a few-cycle orthogonal two-color laser field composed of 800 nm and 400 nm laser pulses. By changing the relative phase of the two laser pulses, a localized enhancement of NSDI yield is observed at 0.5<italic toggle=\"yes\">π</italic> and 1.5<italic toggle=\"yes\">π</italic>, which could be attributed to a rapid and substantial increase in the number of electrons returning to the parent ion within extremely short time intervals at these specific phases. Through the analysis of the electron–electron momentum correlations within different time windows of NSDI events and the angular distributions of emitted electrons in different channels, we observe a more pronounced electron–electron correlation phenomenon in the recollision-induced ionization (RII) channel. This is attributed to the shorter delay time in the RII channel.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"19 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189721","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}
Pub Date : 2024-04-30DOI: 10.1088/1674-1056/ad2d54
Yue Qi, 月 齐, Jian-Hua Wei and 建华 魏
We utilize the calculation of hierarchical equations of motion to demonstrate that the spin-dependent properties between adjacent quantum dots (QDs) can be changed by breaking the internal symmetry configuration, corresponding to the inversion of dominant chiral states. In the linear triple quantum dots (LTQDs) connected to two electron reservoirs, we can observe that the blockage appears at the triangle triple quantum dots (TTQDs) by gradually increasing the coupling strength between next-nearest double QDs. When the initial coupling between LTQDs has altered, the internal chiral circulation also undergoes the corresponding transform, thus achieving qualitative regulation and detection of the blocking region. We also investigate the response of the chiral circulation to the dot–lead coupling strength, indicating the overall robust chiral circulation of the TTQDs frustration.
{"title":"Manipulation of internal blockage in triangular triple quantum dot","authors":"Yue Qi, 月 齐, Jian-Hua Wei and 建华 魏","doi":"10.1088/1674-1056/ad2d54","DOIUrl":"https://doi.org/10.1088/1674-1056/ad2d54","url":null,"abstract":"We utilize the calculation of hierarchical equations of motion to demonstrate that the spin-dependent properties between adjacent quantum dots (QDs) can be changed by breaking the internal symmetry configuration, corresponding to the inversion of dominant chiral states. In the linear triple quantum dots (LTQDs) connected to two electron reservoirs, we can observe that the blockage appears at the triangle triple quantum dots (TTQDs) by gradually increasing the coupling strength between next-nearest double QDs. When the initial coupling between LTQDs has altered, the internal chiral circulation also undergoes the corresponding transform, thus achieving qualitative regulation and detection of the blocking region. We also investigate the response of the chiral circulation to the dot–lead coupling strength, indicating the overall robust chiral circulation of the TTQDs frustration.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"9 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140831782","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}
Pub Date : 2024-04-01DOI: 10.1088/1674-1056/ad1481
Yonggang Wu, Huajian Yu, Zhigang Zheng, Can Xu
The chimera states underlying many realistic dynamical processes have attracted ample attention in the area of dynamical systems. Here, we generalize the Kuramoto model with nonlocal coupling incorporating higher-order interactions encoded with simplicial complexes. Previous works have shown that higher-order interactions promote coherent states. However, we uncover the fact that the introduced higher-order couplings can significantly enhance the emergence of the incoherent state. Remarkably, we identify that the chimera states arise as a result of multi-attractors in dynamic states. Importantly, we review that the increasing higher-order interactions can significantly shape the emergent probability of chimera states. All the observed results can be well described in terms of the dimension reduction method. This study is a step forward in highlighting the importance of nonlocal higher-order couplings, which might provide control strategies for the occurrence of spatial–temporal patterns in networked systems.
{"title":"Chimera states of phase oscillator populations with nonlocal higher-order couplings","authors":"Yonggang Wu, Huajian Yu, Zhigang Zheng, Can Xu","doi":"10.1088/1674-1056/ad1481","DOIUrl":"https://doi.org/10.1088/1674-1056/ad1481","url":null,"abstract":"The chimera states underlying many realistic dynamical processes have attracted ample attention in the area of dynamical systems. Here, we generalize the Kuramoto model with nonlocal coupling incorporating higher-order interactions encoded with simplicial complexes. Previous works have shown that higher-order interactions promote coherent states. However, we uncover the fact that the introduced higher-order couplings can significantly enhance the emergence of the incoherent state. Remarkably, we identify that the chimera states arise as a result of multi-attractors in dynamic states. Importantly, we review that the increasing higher-order interactions can significantly shape the emergent probability of chimera states. All the observed results can be well described in terms of the dimension reduction method. This study is a step forward in highlighting the importance of nonlocal higher-order couplings, which might provide control strategies for the occurrence of spatial–temporal patterns in networked systems.","PeriodicalId":10253,"journal":{"name":"Chinese Physics B","volume":"33 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140560312","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}
Pub Date : 2024-04-01DOI: 10.1088/1674-1056/ad1f4d
Zi-Hang Chen, Jie Sheng, Yu Liu, Xiao-Ming Shi, Houbing Huang, Ke Xu, Yue-Chao Wang, Shuai Wu, Bo Sun, Hai-Feng Liu, Hai-Feng Song
Hydride precipitation in zirconium cladding materials can damage their integrity and durability. Service temperature and material defects have a significant effect on the dynamic growth of hydrides. In this study, we have developed a phase-field model based on the assumption of elastic behaviour within a specific temperature range (613 K–653 K). This model allows us to study the influence of temperature and interfacial effects on the morphology, stress, and average growth rate of zirconium hydride. The results suggest that changes in temperature and interfacial energy influence the length-to-thickness ratio and average growth rate of the hydride morphology. The ultimate determinant of hydride orientation is the loss of interfacial coherency, primarily induced by interfacial dislocation defects and quantifiable by the mismatch degree q. An escalation in interfacial coherency loss leads to a transition of hydride growth from horizontal to vertical, accompanied by the onset of redirection behaviour. Interestingly, redirection occurs at a critical mismatch level, denoted as qc, and remains unaffected by variations in temperature and interfacial energy. However, this redirection leads to an increase in the maximum stress, which may influence the direction of hydride crack propagation. This research highlights the importance of interfacial coherency and provides valuable insights into the morphology and growth kinetics of hydrides in zirconium alloys.
{"title":"Phase-field simulations of the effect of temperature and interface for zirconium δ-hydrides","authors":"Zi-Hang Chen, Jie Sheng, Yu Liu, Xiao-Ming Shi, Houbing Huang, Ke Xu, Yue-Chao Wang, Shuai Wu, Bo Sun, Hai-Feng Liu, Hai-Feng Song","doi":"10.1088/1674-1056/ad1f4d","DOIUrl":"https://doi.org/10.1088/1674-1056/ad1f4d","url":null,"abstract":"Hydride precipitation in zirconium cladding materials can damage their integrity and durability. Service temperature and material defects have a significant effect on the dynamic growth of hydrides. In this study, we have developed a phase-field model based on the assumption of elastic behaviour within a specific temperature range (613 K–653 K). This model allows us to study the influence of temperature and interfacial effects on the morphology, stress, and average growth rate of zirconium hydride. The results suggest that changes in temperature and interfacial energy influence the length-to-thickness ratio and average growth rate of the hydride morphology. The ultimate determinant of hydride orientation is the loss of interfacial coherency, primarily induced by interfacial dislocation defects and quantifiable by the mismatch degree <italic toggle=\"yes\">q</italic>. An escalation in interfacial coherency loss leads to a transition of hydride growth from horizontal to vertical, accompanied by the onset of redirection behaviour. Interestingly, redirection occurs at a critical mismatch level, denoted as <italic toggle=\"yes\">q</italic>\u0000<sub>c</sub>, and remains unaffected by variations in temperature and interfacial energy. However, this redirection leads to an increase in the maximum stress, which may influence the direction of hydride crack propagation. This research highlights the importance of interfacial coherency and provides valuable insights into the morphology and growth kinetics of hydrides in zirconium alloys.","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":"140608874","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}
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.
{"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}
Pub Date : 2024-04-01DOI: 10.1088/1674-1056/ad2604
Jie Hu, Yi-Chen Wang, Qiu-Shuang Jing, Wei Jiang, Ge-Wen Wang, Yi-Wen Zhao, Bo Xiao, Hong-Jing Liang, Ri Ma
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 (ε) in the lower-order harmonics is observed, specifically in the 13rd-order, which displays a maximal harmonic intensity at ε ≈ 0.1, rather than at ε = 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.
{"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}
Pub Date : 2024-04-01DOI: 10.1088/1674-1056/ad1d4d
Heyang Ma, Wanzhou Zhang, Yanting Tian, Chengxiang Ding, Youjin Deng
The two-component cold atom systems with anisotropic hopping amplitudes can be phenomenologically described by a two-dimensional Ising-XY coupled model with spatial anisotropy. At low temperatures, theoretical predictions [Phys. Rev. A72 053604 (2005)] and [arXiv: 0706.1609] indicate the existence of a topological ordered phase characterized by Ising and XY disorder but with 2XY 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 XY-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.
{"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}
Pub Date : 2024-04-01DOI: 10.1088/1674-1056/ad2bfb
Zhuo-Cheng Lu, Ji Feng
A Weyl node is characterized by its chirality and tilt. We develop a theory of how nth-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.
{"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 MnBi<sub>2</sub>Te<sub>4</sub> 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}
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