How to characterize the dynamics of cold atoms in non dissipative optical lattices?

TL;DR

This paper investigates the classical dynamics of cold atoms in non dissipative, time-independent square optical lattices, revealing diverse behaviors including chaos and regular motion, with implications for experimental characterization.

Contribution

It provides a detailed analysis of atom dynamics in non dissipative optical lattices, highlighting the conditions for chaos and regularity, which was less explored in prior studies.

Findings

Chaos can dominate or be negligible inside lattice sites.

Outside sites, chaos may coexist with other dynamical regimes.

Different parameter regimes lead to distinct macroscopic behaviors.

Abstract

We examine here the classical dynamics of cold atoms in square optical lattices, i.e. lattices obtained with two orthogonal stationary plane waves. Contrary to much of the past studies in this domain, the potential is here time independent and non dissipative. We show that, as a function of the experimental parameters, very different behaviors are obtained, both for the dynamics of atoms trapped inside individual sites, and for atoms travelling between sites: inside the sites, chaos may be a main regime or, on the contrary, may be negligible; outside the sites, chaos sometimes coexists with other regimes. We discuss what are the consequences of these differences on the macroscopic behavior of the atoms in the lattice, and we propose experimental measurements able to characterize these dynamics and to distinguish between the different cases.