Routes towards Anderson-Like localization of Bose-Einstein condensates in disordered optical lattices

TL;DR

This paper explores the challenges and potential pathways for observing Anderson-like localization of Bose-Einstein condensates in disordered optical lattices, highlighting the roles of disorder scale and interactions.

Contribution

It provides experimental and theoretical insights into why Anderson localization is not observed in current setups and proposes superlattices as a promising route for future observation.

Findings

No Anderson localization observed with current disordered potentials.

Large disorder length scale and nonlinear interactions screen localization effects.

Incommensurable superlattices may enable observation of Anderson localization.

Abstract

We investigate, both experimentally and theoretically, possible routes towards Anderson-like localization of Bose-Einstein condensates in disordered potentials. The dependence of this quantum interference effect on the nonlinear interactions and the shape of the disorder potential is investigated. Experiments with an optical lattice and a superimposed disordered potential reveal the lack of Anderson localization. A theoretical analysis shows that this absence is due to the large length scale of the disorder potential as well as its screening by the nonlinear interactions. Further analysis shows that incommensurable superlattices should allow for the observation of the cross-over from the nonlinear screening regime to the Anderson localized case within realistic experimental parameters.