Quantum dynamics of Bose-Einstein condensates in tilted and driven bichromatic optical lattices

TL;DR

This paper investigates the complex quantum dynamics of Bose-Einstein condensates in tilted, driven bichromatic optical lattices, focusing on band interactions, tunneling phenomena, and stability issues relevant for quantum technologies.

Contribution

It provides a detailed analysis of the interplay between Bloch oscillations, band transitions, and nonlinear effects in bichromatic lattices, highlighting new insights into condensate stability and tunneling mechanisms.

Findings

Identification of miniband dynamics in bichromatic lattices

Observation of nonlinear Landau-Zener tunneling effects

Mechanisms leading to condensate depletion and instability

Abstract

We study the dynamics of Bose-Einstein condensates in tilted and driven optical superlattices. For a bichromatic lattice, each Bloch band split up into two minibands such that the dynamics is governed by the interplay of Bloch oscillations and transitions between the bands. Thus, bichromatic potentials provide an excellent model system for the study of nonlinear Landau-Zener tunneling and allow for a variety of applications in matter wave interferometry and quantum metrology. In the present paper we investigate the coherent dynamics of an interacting Bose-Einstein condensate as well as its stability. Different mechanisms of instability are discussed, which lead to a rapid depletion of the condensate.