Parastatistics of charged bosons partly localised by impurities

TL;DR

This paper models the thermodynamics of charged bosons in disordered environments, revealing unique phase behaviors including a novel Bose-glass to superfluid transition at finite temperature.

Contribution

It introduces an analytical partition function for localized charged bosons with disorder and predicts a new phase transition between Bose-glass and superfluid states.

Findings

Density of localized bosons varies non-uniformly with temperature

Specific heat exhibits unusual temperature dependence below BEC temperature

A new phase transition from Bose-glass to superfluid at finite temperature

Abstract

Coulomb repulsion is taken into account to derive the thermodynamics of charged bosons in a random external potential. A simple analytical form of the partition function is proposed for the case of non-overlapping localised states (i.e. a small amount of disorder). The density of localised bosons and the specific heat show a peculiar non-uniform temperature dependence below the Bose-Einstein condensation temperature. The superfluid - Bose-glass phase diagram is discussed. A new phase is predicted which is a Bose-glass at T=0 but a superfluid at finite T.