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基础院学术沙龙:Dynamics and steady state properties of quantum correlations in periodically driven Ising spin chain
文:基础与前沿研究院 图:基础与前沿研究院 来源:基础与前沿研究院 时间:2018-04-22 3584

  由基础与前沿研究院主办的学术沙龙第20期邀请到韩国亚太理论物理中心(Asia Pacific Center for Theoretical Physics,简称 APCTP)Utkarsh Mishra博士来校进行学术交流。具体安排如下,欢迎师生们参加!

  主 题:Dynamics and steady state properties of quantum correlations in periodically driven Ising spin chain

  主讲人:Utkarsh Mishra 博士

  时 间:2018年4月24日(周二)15:00

  地 点:沙河校区通信楼818会议室

  主讲人简介:

  Dr Utkarsh Mishra obtained his PhD degree from Harish-Chandra Research Institute, India, in the field of Physics. He is currently working as a postdoctoral research fellow at Asia Pacific Center for Theoretical Physics at Pohang, South Korea. His major areas of research includes: Quantum Information; Many-Body Theory &Many-Body Theory and Correlated Systems Group.

  报告摘要:

  We study the dynamics of microscopic quantum correlations, viz., bipartite entanglement and quantum discord, in Ising spin chain with periodically varying external magnetic field along the transverse direction. Depending upon the system parameters, local quantum correlations in the evolved states of such systems may get saturated to non-zero values after sufficiently large number of driving cycles. Moreover, we investigate convergence of the local density matrices, from which the quantum correlations under study originate, towards the final steady-state density matrices as a function of driving cycles. We find that the geometric distance between the non-equilibrium and the steady-state reduced density matrices obey power-law scaling. The steady-state quantum correlations corresponding to various initial states in thermal equilibrium are studied as a function of drive time period of a square pulsed field. The steady-state quantum correlations are marked by presence of peaks in the frequency domain. The steady-state features can be further understood by probing band structures of Floquet Hamiltonian. Finally, we compare the steady state values of the local quantum correlations under study with that of the canonical Gibbs ensemble and infer about the canonical ergodic properties. We find that depending upon the quantum phases of the initial state and the pathway of the driving Hamiltonian the final values of the long-time quantum correlations may correspond to a canonical Gibbs state. We also find parameter regimes where this correspondence does not hold.


                      基础与前沿研究院

                       2018年4月19日

   

编辑:罗莎  / 审核:林坤  / 发布:陈伟

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