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arXiv · 2111.08671

Thermalization of many many-body interacting SYK models

Jan C. Louw·Stefan Kehrein
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Abstract

We investigate the non-equilibrium dynamics of complex Sachdev-Ye-Kitaev (SYK) models in the $q\rightarrow\infty$ limit, where $q/2$ denotes the order of the random Dirac fermion interaction. We extend previous results by Eberlein et al. [Phys. Rev. B 96, 205123 (2017)] to show that a single SYK $q\rightarrow\infty$ Hamiltonian for $t\geq 0$ is a perfect thermalizer in the sense that the local Green's function is instantaneously thermal. The only memories of the quantum state for $t<0$ are its charge density and its energy density at $t=0$. Our result is valid for all quantum states amenable to a~$1/q$-expansion, which are generated from an equilibrium SYK state in the asymptotic past and acted upon by an arbitrary combination of time-dependent SYK Hamiltonians for $t<0$. Importantly, this implies that a single SYK $q\rightarrow\infty$ Hamiltonian is a perfect thermalizer even for non-equilibrium states generated in this manner.

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Jan C. Louw, Stefan Kehrein. 2021-11-16. Thermalization of many many-body interacting SYK models. https://doi.org/10.1103/physrevb.105.075117

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