Correlations and superfluidity of a one-dimensional Bose gas in a quasiperiodic potential

TL;DR

This paper investigates the correlation functions and superfluid behavior of a one-dimensional Bose gas in a quasiperiodic potential, providing theoretical expressions and analyzing the transition to a Bose glass phase.

Contribution

It introduces a Bogoliubov-based method to derive correlation and superfluid density expressions in arbitrary external potentials, applied specifically to quasiperiodic systems.

Findings

Identifies critical parameters for the Bose glass transition.

Shows Lifshits glass as the limiting case for zero interactions.

Compares two criteria for the transition.

Abstract

We consider the correlations and superfluid properties of a Bose gas in an external potential. Using a Bogoliubov scheme, we obtain expressions for the correlation function and the superfluid density in an arbitrary external potential. These expressions are applied to a one-dimensional system at zero temperature subject to a quasiperiodic modulation. The critical parameters for the Bose glass transition are obtained using two different criteria and the results are compared. The Lifshits glass is seen to be the limiting case for vanishing interactions.