Experimental verification of generalized eigenstate thermalization hypothesis in an integrable system  

作　　者：Qin-Qin Wang Si-Jing Tao Wei-Wei Pan Zhe Chen Geng Chen Kai Sun Jin-Shi Xu Xiao-Ye Xu Yong-Jian Han Chuan-Feng Li Guang-Can Guo 

机构地区：[1]CAS Key Laboratory of Quantum Information,University of Science and Technology of China,Hefei 230026,China [2]CAS Center for Excellence in Quantum Information and Quantum Physics,University of Science and Technology of China,Hefei 230026,China [3]Hefei National Laboratory,University of Science and Technology of China,Hefei 230088,China

出　　处：《Light(Science & Applications)》2022年第7期1615-1624,共10页光（科学与应用)（英文版）

基　　金：supported by Innovation Program for Quantum Science and Technolpgy(No.2021ZD0301200);National Natural Science Foundation of China(Nos.12022401,11874343,62075207,61975195,12122410,92065107,61725504,11774335,11821404);the Fundamental Research Funds for the Central Universities(Nos.W247000030,WK247000034,WK2030380017);the CAS Youth Innovarion Promotion Association(No.2020447);the Anhui Initative in Quantum Information Technologies(No.AHY060300);the Key Program of the Education Department of Anhui Province(No.K2021A0917)。

摘　　要：Identifying the general mechanics behind the equilibration of a complex isolated quantum system towards a state described by only a few parameters has been the focus of attention in non-equilibrium thermodynamics.And several experimentally unproven conjectures are proposed for the statistical description of quantum(non-)integrable models.The plausible eigenstate thermalization hypothesis(ETH),which suggests that each energy eigenstate itself is thermal,plays a crucial role in understanding the quantum thermalization in non-integrable systems;it is commonly believed that it does not exist in integrable systems.Nevertheless,integrable systems can still relax to the generalized Gibbs ensemble.From a microscopic perspective,understanding the origin of this generalized thermalization that occurs in an isolated integrable system is a fundamental open question lacking experimental investigations.Herein,we experimentally investigated the spin subsystem relaxation in an isolated spin-orbit coupling quantum system.By applying the quantum state engineering technique,we initialized the system with various distribution widths in the mutual eigenbasis of the conserved quantities.Then,we compared the steady state of the spin subsystem reached in a long-time coherent dynamics to the prediction of a generalized version of ETH and the underlying mechanism of the generalized thermalization is experimentally verified for the first time.Our results facilitate understanding the origin of quantum statistical mechanics.

关 键 词：INTEGRABLE QUANTUM state 

分 类 号：O413[理学—理论物理]