Quantum dynamics of Gaudin magnets  

作　　者：Wen-Bin He Stefano Chesi Hai-Qing Lin Xi-Wen Guan 

机构地区：[1]Beijing Computational Science Research Center,Beijing 100193,China [2]State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics,Wuhan Institute of Physics and Mathematics,APM,Chinese Academy of Sciences,Wuhan 430071,China [3]The Abdus Salam International Center for Theoretical Physics,Strada Costiera 11,I-34151 Trieste,Italy [4]Department of Physics,Beijing Normal University,Beijing 100875,China [5]NSFC-SPTP Peng Huanwu Center for Fundamental Theory,Xi’an 710127,China [6]Department of Theoretical Physics,Research School of Physics and Engineering,Australian National University,Canberra ACT 0200,Australia

出　　处：《Communications in Theoretical Physics》2022年第9期39-48,共10页理论物理通讯（英文版）

基　　金：support from NSAF(Grant No.U1930402);supported by the key NSFC grant No.12134015 and No.11874393;the National Key R&D Program of China No.2017YFA0304500,the National Key R&D Program of China No.2016YFA0301200;support from NSFC(Grants No.11974040 and No.12150610464),NSFC 11734002;financial support from National Science Association Funds U1930402

摘　　要：Quantum dynamics of many-body systems is a fascinating and significant subject for both theory and experiment.The question of how an isolated many-body system evolves to its steady state after a sudden perturbation or quench still remains challenging.In this paper,using the Bethe ansatz wave function,we study the quantum dynamics of an inhomogeneous Gaudin magnet.We derive explicit analytical expressions for various local dynamic quantities with an arbitrary number of flipped bath spins,such as:the spin distribution function,the spin-spin correlation function,and the Loschmidt echo.We also numerically study the relaxation behavior of these dynamic properties,gaining considerable insight into coherence and entanglement between the central spin and the bath.In particular,we find that the spin-spin correlations relax to their steady value via a nearly logarithmic scaling,whereas the Loschmidt echo shows an exponential relaxation to its steady value.Our results advance the understanding of relaxation dynamics and quantum correlations of long-range interacting models of the Gaudin type.

关 键 词：Gaudin magnets central spin model Bethe ansatz spin polarization spin-spin correlation Loschmidt echo 

分 类 号：O469[理学—凝聚态物理]