Dynamical instability, Chaos, and Bloch oscillations of Bose-Einstein condensates in tilted optical lattices

TL;DR

This paper investigates the dynamics of Bose-Einstein condensates in tilted optical lattices, revealing regimes of exponential decay and quasiperiodic oscillations linked to chaos onset, using the discrete nonlinear Schrödinger equation.

Contribution

It introduces a detailed analysis of Bloch oscillations in BECs, connecting static force strength to dynamical regimes and chaos, which advances understanding of nonlinear quantum systems.

Findings

Exponential decay occurs below a critical static force magnitude.

Quasiperiodic oscillations occur above the critical force.

Chaos onset correlates with transition between oscillation regimes.

Abstract

We study the Bloch dynamics of a Bose-Einstein condensate of cold atoms by using the formalism of the discrete nonlinear Schroedinger equation. Depending on the static force magnitudes the system is shown to exhibit two qualitatively different regimes of Bloch oscillations - exponential decay for the static force magnitude less than some critical value (defined by the condensate density) and quasiperiodic oscillations in the opposite case. The relation of these regimes to the onset of chaos in the system is discussed.