# Quantum quench of the Sachdev-Ye-Kitaev Model

## TL;DR

This paper investigates the non-equilibrium dynamics of the Sachdev-Ye-Kitaev models, revealing thermalization behavior and providing exact solutions in the large q limit, advancing understanding of quantum systems without quasiparticles.

## Contribution

It offers a detailed analysis of quantum quench dynamics in SYK models, including numerical and exact solutions, highlighting thermalization processes in these complex systems.

## Key findings

- Final state is thermal according to Kadanoff-Baym equations
- Thermalization rate is proportional to the absolute temperature
- In the large q limit, thermalization of Green's function is instantaneous

## Abstract

We describe the non-equilibrium dynamics of the Sachdev-Ye-Kitaev models of fermions with all-to-all interactions. These provide tractable models of the dynamics of quantum systems without quasiparticle excitations. The Kadanoff-Baym equations show that the final state is thermal, and their numerical analysis appears consistent with a thermalization rate proportional to the absolute temperature of the final state. We also obtain an exact analytic solution of the non-equilibrium dynamics in the large $q$ limit of a model with $q$ fermion interactions: in this limit, the thermalization of the fermion Green's function is instantaneous.