Probing the edge between integrability and quantum chaos in interacting few-atom systems

TL;DR

This paper investigates how quantum chaos emerges in a minimal, tunable model of interacting cold atoms in multi-well potentials, revealing the transition from integrability to chaos with increasing particles and wells.

Contribution

It introduces a simple, experimentally realizable model to study the onset of quantum chaos in few-body systems, bridging the gap between integrability and chaos.

Findings

Quantum chaos signatures appear with 3 particles and become stronger with 4.

The model is highly tunable via particle number and potential wells.

Analysis applies to bosons and can extend to fermions.

Abstract

Interacting quantum systems in the chaotic domain are at the core of various ongoing studies of many-body physics, ranging from the scrambling of quantum information to the onset of thermalization. We propose a minimum model for chaos that can be experimentally realized with cold atoms trapped in one-dimensional multi-well potentials. We explore the emergence of chaos as the number of particles is increased, starting with as few as two, and as the number of wells is increased, ranging from a double well to a multi-well Kronig-Penney-like system. In this way, we illuminate the narrow boundary between integrability and chaos in a highly tunable few-body system. We show that the competition between the particle interactions and the periodic structure of the confining potential reveals subtle indications of quantum chaos for 3 particles, while for 4 particles stronger signatures are seen. The analysis is performed for bosonic particles and could also be extended to distinguishable fermions.