学术活动

Many-body localization and thermalization in disordered Hubbard chains

作者:点击次数:更新时间:2016年05月18日

报告人:Rubem Mondaini,北京计算科学研究中心,研究助理教授

报告时间:2016.5.26(周四)下午4点

报告地点:LE523

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摘要:In this talk, I will revise some of the aspects of the many-body localization phenomena highlighting some known results and its connection with recent experimental evidences in optical lattices.Before describing its theoretical evidences I will show what are the conditions that lead isolated interacting quantum systems to thermalize. In the presence of disorder, however, the thermalization process fails resulting in a phenomena where transport is suppressed known as many-body localization. Unlike the standard Anderson localization for non-interacting systems, the delocalized (ergodic) phase is very robust against disorder even for moderate values of interaction. Another interesting aspect of the many-body localization phase is that under the time evolution of the quenched disorder, information present in the initial state may survive for arbitrarily long times. This was recently used as a probe of many-body localization of ultracold fermions in optical lattices with quasi-periodic disorder [1]. Here, we will stress that this analysis may suffer from substantial finite-size effects after comparing with the numerical results in one-dimensional Hubbard chains [2].

References:

[1] - M.Schreiber, S. S. Hodgman,. P. Bordia,.H. P. Lüschen, M. H. Fischer, R. Vosk, E. Altman, U. Schneider, I. Bloch, Science 349, 842 (2015)

[2] - Rubem Mondaini and Marcos Rigol, Physical Review A 92, 041601(R) (2015) - Editor’s suggestion

报告人简介:

Graduate at Physics from Federal University of Rio de Janeiro (2006), Master’s at Physics from Federal University of Rio de Janeiro (2008) and DSc. at Physics from Federal University of Rio de Janeiro (2012) acting on the following subjects: Strongly Correlated Electron Systems,

Magnetic Multilayers, Transport Properties in Many-Body Systems, Disorder in Graphene and Superconductivity in Cuprates. In the past year started investigating the out-of-equilibrium dynamics in Strongly Correlated Systems, including the aspects of thermalization and its breakdown on the

presence of disorder in the so-called many-body localization phenomena. My Research can be summarized as being a theoretical investigation in many-body systems supported by numerical simulations. The techniques, essentially without any bias, range from Exact Diagonalization (using spatial symmetries) to Quantum Monte Carlo (either for finite or zero temperature).