Signatures of quantum chaos in low-energy mixtures of few fermions

TL;DR

This paper investigates how quantum chaos manifests in the low-energy behavior of a few ultracold fermions in a double-well potential, revealing signatures that depend on particle number and imbalance.

Contribution

It provides the first detailed analysis of quantum chaos signatures in a simple, experimentally relevant few-fermion system with varying particle distributions.

Findings

Signatures of quantum chaos appear even with three particles.

Quantum chaos signatures are enhanced with balanced fermion distribution.

Signatures are suppressed as particle imbalance increases.

Abstract

The low energy dynamics of mesoscopic systems strongly depends on the presence of internal equilibration. For this reason, a better interpretation of ultracold atom experiments requires a more accurate understanding of how quantum chaos manifests itself in these systems. In this paper, we consider a simple but experimentally relevant one-dimensional system of a few ultracold fermions moving in a double-well potential. We analyze its many-body spectral properties, which are commonly used to trace quantum chaos. We observe some signatures of quantum chaos already in the system with three particles. Generally, these signatures become more pronounced when fermions are evenly added to both components. On the contrary, they become suppressed when the particle imbalance is increased.