Breakdown of Anderson localization in the transport of Bose-Einstein condensates through one-dimensional disordered potentials

TL;DR

This paper investigates how interactions affect Anderson localization in Bose-Einstein condensates moving through 1D disordered potentials, revealing a transition from localized to delocalized transport with increasing interaction strength.

Contribution

It demonstrates the validity of the truncated Wigner method for many-body transport and uncovers the interaction-driven crossover from localized to incoherent transport.

Findings

Weak interactions preserve Anderson localization with modified localization length.

Strong interactions induce a transition to a delocalized, incoherent transport regime.

Semiclassical corrections beyond the diagonal approximation are negligible under disorder averaging.

Abstract

We study the transport of an interacting Bose--Einstein condensate through a 1D correlated disorder potential. We use for this purpose the truncated Wigner method, which is, as we show, corresponding to the diagonal approximation of a semiclassical van Vleck-Gutzwiller representation of this many-body transport process. We also argue that semiclassical corrections beyond this diagonal approximation are vanishing under disorder average, thus confirming the validity of the truncated Wigner method in this context. Numerical calculations show that, while for weak atom-atom interaction strength Anderson localization is preserved with a slight modification of the localization length, for larger interaction strenghts a crossover to a delocalized regime exists due to inelastic scattering. In this case, the transport is fully incoherent.