Finite temperature phase transition for disordered weakly interacting bosons in one dimension

TL;DR

This paper demonstrates a finite temperature phase transition in a disordered 1D bosonic system, revealing how interactions influence localization and transport properties, contrary to the traditional belief of no phase transitions in 1D at finite temperature.

Contribution

It shows that disordered 1D bosons can undergo a true phase transition between fluid and insulator states at finite temperature, driven by interactions and disorder.

Findings

Identifies a finite temperature phase transition in 1D disordered bosons.

Distinguishes fluid and insulator phases based on transport properties.

Highlights the role of interactions in Anderson localization in 1D systems.

Abstract

It is commonly accepted that there are no phase transitions in one-dimensional (1D) systems at a finite temperature, because long-range correlations are destroyed by thermal fluctuations. Here we demonstrate that the 1D gas of short-range interacting bosons in the presence of disorder can undergo a finite temperature phase transition between two distinct states: fluid and insulator. None of these states has long-range spatial correlations, but this is a true albeit non-conventional phase transition because transport properties are singular at the transition point. In the fluid phase the mass transport is possible, whereas in the insulator phase it is completely blocked even at finite temperatures. We thus reveal how the interaction between disordered bosons influences their Anderson localization. This key question, first raised for electrons in solids, is now crucial for the studies of atomic bosons where recent experiments have demonstrated Anderson localization in expanding very dilute quasi-1D clouds.