Delayed Thermalization in Mass-Deformed SYK

TL;DR

This paper investigates how the mass-deformed SYK model exhibits delayed but eventual thermalization, providing evidence that many-body localization can be viewed as Fock-space localization, with implications for understanding ergodicity breaking.

Contribution

It demonstrates through numerical analysis that the mass-deformed SYK model shows delayed thermalization, supporting the view of many-body localization as Fock-space localization.

Findings

Thermalization occurs but is significantly delayed in the model.

Eigenstates are ergodically extended over limited Fock space regions.

Supports the hypothesis that many-body localization is Fock-space localization.

Abstract

We study the thermalizing properties of the mass-deformed SYK model, in a regime of parameters where the eigenstates are ergodically extended over just portions of the full Fock space, as an all-to-all toy model of many-body localization. Our numerical results strongly support the hypothesis that, although considerably delayed, thermalization is still present in this regime. Our results add to recent studies indicating that many-body localization should be interpreted as a strict Fock-space localization.