【报告题目】Mesoscopic fluctuations in entanglement dynamics
【报告人】林励庆(Lih-King Lim) 浙江大学物理学院
【时间】2023年9月6日(周三)下午14:30-15:30
【主办方】浙江光电子研究院 浙江师范大学
【线下地点】光电子研究院302报告厅(北山路285号)
【报告摘要】In this talk, we will describe our recent work [1] in studying the long-time evolution of entanglement entropy in a class of integrable lattice fermion models subjected to a sudden quench. Even though the out-of-equilibrium fluctuations in entanglement is expected to differ conceptually from traditional physical quantities, their studies remain elusive. Here we uncover a random structure emergent from the wavefunction evolution, leading to fluctuations in entanglement which, strikingly, fall into the paradigm of mesoscopic fluctuations. We will discuss how unitary dynamical evolution can lead to fluctuations that can be traded with mesoscopic sample-to-sample fluctuations description. We find that the entanglement entropy variance obeys a universal scaling law, and the full distribution has a universal shape, displaying a sub-Gaussian upper and a sub-Gamma lower tail. Not only are these statistical behaviors independent of system's microscopic details, but also independent of the choice of entanglement probes (e.g., R\'enyi entropy), and thus they broaden mesoscopic universalities. Our findings indicate that quantum coherence leads to the ubiquity of entanglement fluctuations in an out-of-equilibrium quantum systems.
Ref: [1] L.-K. Lim, C. Lou, and C. Tian, arXiv:2305.09962
【报告人简介】Dr. Lih-King Lim obtained his PhD degree in theoretical physics in Utrecht University, the Netherlands in 2010. He spent several years of postdoc researches in Laboratoire Physique des Solides, Orsay, France (2010-2012), Institut d'Optique, Palaiseau, France (2012-2014), and Max Planck Institute for the Physics of Complex Systems, Dresden, Germany (2014-2015). He was an associate member (2015-2017) at Institute of Advanced Study Tsinghua University, Beijing. Since 2018, he is an assistant professor in the School of Physics, Zhejiang University. His research interests include topological/geometric effects in quantum matter as realized in both cold atomic and condensed matter systems. Artificial gauge fields in cold atoms, Landau-Zener transitions in Dirac cone systems, pseudospin models for topological semimetals. Recently, he works on quantum dynamics of entanglement behavior in quantum simulators.