Nonlinear Transport of Bose-Einstein Condensates Through Waveguides with Disorder

TL;DR

This paper investigates how Bose-Einstein condensates move through disordered waveguides, revealing different transport behaviors depending on interaction strength and disorder length, with implications for quantum transport experiments.

Contribution

It introduces a realistic disordered potential model based on magnetic fluctuations and analyzes nonlinear transport regimes of condensates in microfabricated guides.

Findings

Transmission decays exponentially with length at low interactions

Transition to time-dependent flow occurs at high interactions or large length

Algebraic decay of transmission in the time-dependent regime

Abstract

We study the coherent flow of a guided Bose-Einstein condensate incident over a disordered region of length L. We introduce a model of disordered potential that originates from magnetic fluctuations inherent to microfabricated guides. This model allows for analytical and numerical studies of realistic transport experiments. The repulsive interaction among the condensate atoms in the beam induces different transport regimes. Below some critical interaction (or for sufficiently small L) a stationary flow is observed. In this regime, the transmission decreases exponentially with L. For strong interaction (or large L), the system displays a transition towards a time dependent flow with an algebraic decay of the time averaged transmission.