Time-of-flight images of Mott insulators in the Hofstadter-Bose-Hubbard model

TL;DR

This paper investigates how the momentum distribution in Mott insulators within the Hofstadter-Bose-Hubbard model depends on artificial gauge fields, comparing approximation methods to identify significant corrections.

Contribution

It provides a detailed comparison between RPA and SCE methods for analyzing gauge-dependent momentum distributions in Mott insulators.

Findings

RPA results show notable corrections in two dimensions.

Benchmarking reveals the importance of strong-coupling effects.

Gauge dependence significantly influences the momentum distribution.

Abstract

We analyze the momentum distribution function and its artificial-gauge-field dependence for the Mott insulator phases of the Hofstadter-Bose-Hubbard model. By benchmarking the results of the random-phase approximation (RPA) approach against those of the strong-coupling expansion (SCE) for the Landau and symmetric gauges, we find pronounced corrections to the former results in two dimensions.