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arXiv · 1805.03675

Chaos and High Temperature Pure State Thermalization

Yuri D. Lensky·Xiao-Liang Qi
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Abstract

Classical arguments for thermalization of isolated systems do not apply in a straightforward way to the quantum case. Recently, there has been interest in diagnostics of quantum chaos in many- body systems. In the classical case, chaos is a popular explanation for the legitimacy of the methods of statistical physics. In this work, we relate a previously proposed criteria of quantum chaos in the unitary time evolution operator to the entanglement entropy growth for a far-from-equilibrium initial pure state. By mapping the unitary time evolution operator to a doubled state, chaos can be characterized by suppression of mutual information between subsystems of the past and that of the future. We show that when this mutual information is small, a typical unentangled initial state will evolve to a highly entangled final state. Our result provides a more concrete connection between quantum chaos and thermalization in many-body systems.

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Yuri D. Lensky, Xiao-Liang Qi. 2018-07-05. Chaos and High Temperature Pure State Thermalization. https://doi.org/10.1007/jhep06(2019)025

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