Superfluid-insulator transition of two-dimensional disordered Bose gases

TL;DR

This paper investigates the superfluid-insulator transition in two-dimensional disordered Bose gases, revealing a critical disorder strength where the system transitions from superfluid to Bose glass, characterized by changes in the density of states.

Contribution

The study provides large-scale simulations showing the behavior of the density of states and identifies the critical disorder strength for the superfluid to Bose glass transition in 2D disordered Bose gases.

Findings

Density of states remains quadratic up to critical disorder

Power-law behavior with disorder-dependent exponent beyond threshold

Transition from superfluid to Bose glass identified

Abstract

We study the two-dimensional weakly repulsive Bose gas at zero temperature in the presence of correlated disorder. Using large-scale simulations, we show that the low-energy Bogoliubov cumulative density of states remains quadratic up to a critical disorder strength, beyond which a power law with disorder-dependent exponent $\beta<2$ sets in. We associate this threshold behavior with the transition from superfluid to Bose glass, and compare the resulting mean-field phase diagram with scaling laws and the Thomas-Fermi percolation threshold of the mean-field density profile.