Thermalization and its Breakdown for a Large Nonlinear Spin

ORAL

Abstract

By developing a semi-classical analysis based on the Eigenstate Thermalization Hypothesis, we determine the long time behavior of a large spin evolving with a nonlinear Hamiltonian. Despite integrable classical dynamics, we find the Eigenstate Thermalization Hypothesis is satisfied in the majority of eigenstates and thermalization is generic. The exception is a novel mechanism for the breakdown of thermalization based on an unstable fixed point in the classical dynamics. Using the semi-classical analysis we derive how the equilibrium values of observables encode properties of the initial state. We conclude with a discussion of relevant experiments and the potential generality of this mechanism for the breakdown of thermalization.

Arxiv 1910.03138

*This work was supported in part by the NSF under Grant No. DMR-1411345, S. P. K. acknowledges financial support from the UC Office of the
President through the UC Laboratory Fees Research Program, Award Number LGF-17- 476883. The research of E. T. in the work presented in this manuscript was supported by the Laboratory Directed Research and Development program of Los Alamos National Laboratory under project number 20180045DR.

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Presenters

  • Shane Kelly

    • University of California, Riverside
    • Los Alamos National Laboratory

Authors

  • Shane Kelly

    • University of California, Riverside
    • Los Alamos National Laboratory

  • Shan-Wen Tsai

    • University of California, Riverside
    • Physics and Astronomy, University of California Riverside

  • Eddy M.E. Timmermans

    • Los Alamos National Laboratory