Physical Review最新文献_第9页

Thermal effects on the spin-domain phases of high spin- f Bose-Einstein condensates with rotational symmetries 具有旋转对称性的高自旋f玻色-爱因斯坦凝聚体自旋域相的热效应

Physical Review Pub Date : 2023-11-09 DOI: 10.1103/physreva.108.053308

Eduardo Serrano-Ensástiga, Francisco Mireles

引用次数: 0

Ratchet current in a PT -symmetric Floquet quantum system with symmetric sinusoidal driving 对称正弦驱动PT对称Floquet量子系统的棘轮电流

Physical Review Pub Date : 2023-11-09 DOI: 10.1103/physreva.108.052211

Zhiqiang Li, Xiaoxiao Hu, Jinpeng Xiao, Yajiang Chen, Xiaobing Luo

{"title":"Ratchet current in a PT -symmetric Floquet quantum system with symmetric sinusoidal driving","authors":"Zhiqiang Li, Xiaoxiao Hu, Jinpeng Xiao, Yajiang Chen, Xiaobing Luo","doi":"10.1103/physreva.108.052211","DOIUrl":"https://doi.org/10.1103/physreva.108.052211","url":null,"abstract":"We consider the ratchet dynamics in a $mathcal{PT}$-symmetric Floquet quantum system with symmetric temporal (harmonic) driving. In the exact $mathcal{PT}$-symmetry phase, for a finite number of resonant frequencies, we show that the long-lasting resonant currents can be generated with the symmetric time-continuous driving, which would otherwise forbid the generation of directed currents in the Hermitian limit. Such a non-Hermitian resonant current can be enhanced by increasing the non-Hermitian level and, in particular, the resonant current peaks (reaches the largest negative value) under the condition that the imaginary part of the potential depth is equal to the real part, at which the stable asymptotic current occurs owing to exceptional points mechanism. Moreover, the directed currents originating from the symmetry breaking are reported, which increase linearly with the driving frequency, the mechanism behind which is that the cutoff of the momentum eigenstates for the Floquet state with maximum imaginary quasienergy increases as the driving frequency is continuously increased. We also present a non-Hermitian three-level model that can account for the resonant currents and gives surprisingly good agreement with direct numerical results for weak driving, even in the broken-$mathcal{PT}$-symmetry regime for the first-order resonance. Our results provide a means of realizing the non-Hermiticity-controlled ratchet current by means of a smooth continuous driving, previously used only to generate currents in Hermitian systems.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":" 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135291277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Unconventional saturation effects at intermediate drive in a lossy cavity coupled to few emitters 耦合少量发射体的损耗腔中中等驱动的非常规饱和效应

Physical Review Pub Date : 2023-11-09 DOI: 10.1103/physreva.108.053706

Therese Karmstrand, Benjamin Rousseaux, Anton Frisk Kockum, Timur Shegai, Göran Johansson

{"title":"Unconventional saturation effects at intermediate drive in a lossy cavity coupled to few emitters","authors":"Therese Karmstrand, Benjamin Rousseaux, Anton Frisk Kockum, Timur Shegai, Göran Johansson","doi":"10.1103/physreva.108.053706","DOIUrl":"https://doi.org/10.1103/physreva.108.053706","url":null,"abstract":"Recent technological advancements have enabled strong light-matter interaction in highly dissipative cavity-emitter systems. However, in these systems, which are well described by the Tavis-Cummings model, the considerable loss rates render the realization of many desirable nonlinear effects, such as saturation and photon blockade, problematic. Here we present another effect occurring within the Tavis-Cummings model: A nonlinear response of the cavity for resonant external driving of intermediate strength, which makes use of large cavity dissipation rates. In this regime, $(N+1)$-photon absorption processes dominate when the cavity couples to $N$ emitters. We explore and characterize this effect in detail, and provide a picture of how the effect occurs due to destructive interference between the emitter ensemble and the external drive. We find that a central condition for the observed effect is large cooperativity; i.e., the product of the cavity and emitter decay rates is much smaller than the collective cavity-emitter interaction strength squared. Importantly, this condition does not require strong coupling. We also find an analytical expression for the critical drive strength at which the effect appears. Our results have potential for quantum state engineering, e.g., photon filtering, and could be used for the characterization of cavity-emitter systems where the number of emitters is unknown. In particular, our results open the way for investigations of unique quantum-optics applications in a variety of platforms that require neither high-quality cavities nor strong coupling.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":" 88","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135191537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Observation of the knot topology of non-Hermitian systems in a single spin 单自旋非厄米系统的结拓扑观察

Physical Review Pub Date : 2023-11-09 DOI: 10.1103/physreva.108.052409

Yang Wu, Yunhan Wang, Xiangyu Ye, Wenquan Liu, Chang-Kui Duan, Ya Wang, Xing Rong, Jiangfeng Du

引用次数: 1

Goal quest for an intelligent surfer moving in a chaotic flow 一个在混乱流中移动的智能冲浪者的目标任务

Physical Review Pub Date : 2023-11-09 DOI: 10.1103/physreve.108.054212

Klaus M. Frahm, Dima L. Shepelyansky

引用次数: 0

Impact of social distancing on disease transmission risk in the context of a pandemic 大流行背景下保持社会距离对疾病传播风险的影响

Physical Review Pub Date : 2023-11-09 DOI: 10.1103/physreve.108.054115

Chuan-Yao Li, Jie Yin, Liang Chen

{"title":"Impact of social distancing on disease transmission risk in the context of a pandemic","authors":"Chuan-Yao Li, Jie Yin, Liang Chen","doi":"10.1103/physreve.108.054115","DOIUrl":"https://doi.org/10.1103/physreve.108.054115","url":null,"abstract":"Changes in pedestrian dynamics caused by social distancing policies place new demands on pedestrian motion modeling during the pandemic. This study summarizes pedestrian movement characteristics during the pandemic, based on which, the traditional floor-field cellular automata model was improved by introducing two floor fields related to pedestrian density to simulate social distancing in crowded places. Especially, the cumulative density field guides pedestrians in route selection, thereby compensating for the limitation of the previous models in which only local repulsion was considered. By selecting an appropriate combination of parameters, the desired social distancing behavior can be observed. Then, the rationality of our model is verified by the fundamental diagram. Moreover, to assess the influences of social distancing on the risk of disease transmission, we considered both person-person transmission and environment-person transmission. The simulation results show that although social distancing is effective in preventing interpersonal transmission, an increase in environmental transmission may somewhat offset this effect. We also examined the influence of individual motion heterogeneity on infection spread and found that the containment was the best when only patients complied with the social distancing restriction. The trade-off between safety and efficiency associated with social distancing was also initially explored in this study.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":" 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135291151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Statistics of the number of renewals, occupation times, and correlation in ordinary, equilibrium, and aging alternating renewal processes 统计普通、均衡和老化交替更新过程中的更新次数、占用时间和相关性

Physical Review Pub Date : 2023-11-08 DOI: 10.1103/physreve.108.054113

Takuma Akimoto

{"title":"Statistics of the number of renewals, occupation times, and correlation in ordinary, equilibrium, and aging alternating renewal processes","authors":"Takuma Akimoto","doi":"10.1103/physreve.108.054113","DOIUrl":"https://doi.org/10.1103/physreve.108.054113","url":null,"abstract":"The renewal process is a point process where an interevent time between successive renewals is an independent and identically distributed random variable. Alternating renewal process is a dichotomous process and a slight generalization of the renewal process, where the interevent time distribution alternates between two distributions. We investigate statistical properties of the number of renewals and occupation times for one of the two states in alternating renewal processes. When both means of the interevent times are finite, the alternating renewal process can reach an equilibrium. On the other hand, an alternating renewal process shows aging when one of the means diverges. We provide analytical calculations for the moments of the number of renewals, occupation time statistics, and the correlation function for several case studies in the interevent-time distributions. We show anomalous fluctuations for the number of renewals and occupation times when the second moment of interevent time diverges. When the mean interevent time diverges, distributional limit theorems for the number of events and occupation times are shown analytically. These are known as the Mittag-Leffler distribution and the generalized arcsine law in probability theory.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":"83 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135341677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comment on “Multitime quantum communication: Interesting but not counterfactual” 评《多时间量子通信:有趣但不反事实》

Physical Review Pub Date : 2023-11-08 DOI: 10.1103/physreva.108.056201

Lev Vaidman

引用次数: 1

Nonlinear multistate tunneling dynamics in a spinor Bose-Einstein condensate 旋量玻色-爱因斯坦凝聚体中的非线性多态隧道动力学

Physical Review Pub Date : 2023-11-08 DOI: 10.1103/physreva.108.053307

Z. N. Hardesty-Shaw, Q. Guan, J. O. Austin-Harris, D. Blume, R. J. Lewis-Swan, Y. Liu

引用次数: 1

Coexistence of Gaussian and non-Gaussian statistics in vector integrable turbulence 矢量可积湍流中高斯和非高斯统计量的共存

Physical Review Pub Date : 2023-11-08 DOI: 10.1103/physreve.108.054211

Zhi-Yuan Sun, Xin Yu, Yu-Jie Feng

引用次数: 0