Imaginary Time Crystal of Thermal Quantum Matter  

作　　者：Zi Cai Yizhen Huang WVincent Liu 蔡子;黄易珍;刘文胜(Wilczek Quantum Center and Key Laboratory of Artificial Structures and Quantum Control,School of Physics and Astronomy,Shanghai Jiao Tong University,Shanghai 200240;Shanghai Research Center for Quantum Sciences,Shanghai 201315;Department of Physics and Astronomy,University of Pittsburgh,Pittsburgh,Pennsylvania 15260,USA;Wilczek Quantum Center,School of Physics and Astronomy and T.D.Lee Institute,Shanghai Jiao Tong University,Shanghai 200240)

机构地区：[1]Wilczek Quantum Center and Key Laboratory of Artificial Structures and Quantum Control,School of Physics and Astronomy,Shanghai Jiao Tong University,Shanghai 200240 [2]Shanghai Research Center for Quantum Sciences,Shanghai 201315 [3]Department of Physics and Astronomy,University of Pittsburgh,Pittsburgh,Pennsylvania 15260,USA [4]Wilczek Quantum Center,School of Physics and Astronomy and T.D.Lee Institute,Shanghai Jiao Tong University,Shanghai 200240

出　　处：《Chinese Physics Letters》2020年第5期28-32,共5页中国物理快报（英文版）

基　　金：National Key Research and Development Program of China(Grant No.2016YFA0302001);National Natural Science Foundation of China(Grant Nos.11674221 and 11745006);Shanghai Rising-Star Program;Eastern Scholar Professor of Distinguished Appointment Program;the AFOSR(Grant No.FA9550-16-1-0006);MURI-ARO(Grant No.W911NF-17-1-0323);through UC Santa Barbara,the NSF China Overseas Scholar Collaborative Program(Grant No.11429402);Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)。

摘　　要：Temperature is a fundamental thermodynamic variable for matter.Physical observables are often found to either increase or decrease with it,or show a non-monotonic dependence with peaks signaling underlying phase transitions or anomalies.Statistical Held theory has established connection between temperature and time:a quantum ensemble with inverse temperatureβis formally equivalent to a dynamic system evolving along an imaginary time from 0 to iβin the space one dimension higher.Here we report that a gas of hard-core bosons interacting with a thermal bath manifests an unexpected temperature-periodic oscillation of its macroscopic observables,arising from the microscopic origin of space-time locked translational symmetry breaking and crystalline ordering.Such a temperature crystal,supported by quantum Monte Carlo simulation,generalizes the concept of purely spatial density-wave order to the imaginary time axis for Euclidean action.

关 键 词：imaginary QUANTUM OBSERVABLE 

分 类 号：O413.1[理学—理论物理]