Glassy behavior in a binary atomic mixture

TL;DR

This study compares the effects of uncorrelated and correlated disorder on one-dimensional Bose gases, revealing that correlations significantly influence the superfluid-to-insulator transition and Bose glass formation.

Contribution

It provides experimental evidence on how disorder correlations affect phase transitions in 1D Bose gases, highlighting the importance of correlations in disordered quantum systems.

Findings

Uncorrelated disorder shifts the critical lattice depth for transport breakdown.

Correlated quasi-disorder does not shift the critical point.

Both disorder types show signatures of Bose glass formation in the strongly interacting regime.

Abstract

We experimentally study one-dimensional, lattice-modulated Bose gases in the presence of an uncorrelated disorder potential formed by localized impurity atoms, and compare to the case of correlated quasi-disorder formed by an incommensurate lattice. While the effects of the two disorder realizations are comparable deeply in the strongly interacting regime, both showing signatures of Bose glass formation, we find a dramatic difference near the superfluid-to-insulator transition. In this transition region, we observe that random, uncorrelated disorder leads to a shift of the critical lattice depth for the breakdown of transport as opposed to the case of correlated quasi-disorder, where no such shift is seen. Our findings, which are consistent with recent predictions for interacting bosons in one dimension, illustrate the important role of correlations in disordered atomic systems.