Prethermalization with negative specific heat

TL;DR

This paper investigates non-canonical relaxation in a composite cold atoms system with negative specific heat, revealing prethermalization driven by adiabatic invariants and the Thirring instability, which pushes subsystems toward spectral edges.

Contribution

It demonstrates how negative specific heat subsystems lead to prethermalization far from integrability, highlighting the role of adiabatic invariants and the Thirring instability in this process.

Findings

Prethermalization occurs far from integrability due to adiabatic invariants.

Thirring instability causes subsystems to approach spectral edges.

Contrast between prethermal and thermal states is significantly enhanced.

Abstract

We study non-canonical relaxation in a composite cold atoms system, consisting of subsystems that possess negative microcanonical specific heat. The system exhibits pre-thermalization far away from integrability due to the appearance of a single adiabatic invariant. The Thirring instability drives the constituent subsystems towards the edges of their allowed energy spectrum, thus greatly enhancing the contrast between the prethermal state and the long time thermal outcome.