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arXiv · 2202.01845

Maximal quantum chaos of the critical Fermi surface

Maria Tikhanovskaya·Subir Sachdev·Aavishkar A. Patel
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Abstract

We investigate the many-body quantum chaos of non-Fermi liquid states with Fermi surfaces in two spatial dimensions by computing their out-of-time-order correlation functions. Using a recently proposed large $N$ theory for the critical Fermi surface, and the ladder identity of Gu and Kitaev, we show that the chaos Lyapunov exponent takes the maximal value of $2 \pi k_B T/\hbar$, where $T$ is the absolute temperature. We also examine a phenomenological model in which the chaos exponent becomes smaller than the maximal value precisely when quasiparticles are restored.

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Maria Tikhanovskaya, Subir Sachdev, Aavishkar A. Patel. 2022-02-01. Maximal quantum chaos of the critical Fermi surface. https://doi.org/10.1103/physrevlett.129.060601

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