Bose-Bose mixtures in a weak-disorder potential: Fluctuations and superfluidity

TL;DR

This paper investigates how weak disorder affects the properties of a homogeneous Bose-Bose mixture at zero temperature, revealing modifications to miscibility, superfluidity, and localization due to disorder and interactions.

Contribution

It introduces a perturbative analysis of disorder effects on Bose-Bose mixtures, highlighting how disorder alters miscibility conditions and superfluid properties.

Findings

Disorder modifies the miscibility-immiscibility condition.

Full miscibility is impossible in the presence of disorder.

Disorder influences localization, quantum fluctuations, and superfluidity.

Abstract

We study the properties of a homogeneous dilute Bose-Bose gas in a weak-disorder potential at zero temperature. By using the perturbation theory, we calculate the disorder corrections to the condensate density, the equation of state, the compressibility, and the superfluid density as a function of density, strength of disorder, and miscibility parameter. It is found that the disorder potential may lead to modifying the miscibility-immiscibility condition and a full miscible phase turns out to be impossible in the presence of the disorder. We show that the intriguing interplay of the disorder and intra- and interspecies interactions may strongly influence the localization of each component, the quantum fluctuations, and the compressibility, as well as the superfluidity of the system.