Meissner effect in a charged Bose gas with short-range repulsion

TL;DR

This paper investigates whether Bose-Einstein condensation (BEC) is essential for the Meissner effect in a charged Bose gas, finding that the Meissner effect can occur prior to BEC due to growing coherence.

Contribution

It demonstrates that the Meissner effect can occur without BEC in a charged Bose gas with short-range repulsion, challenging previous assumptions.

Findings

Susceptibility shows a singularity before BEC occurs

The Meissner effect is possible without BEC in this system

Growing coherence leads to the Meissner effect prior to BEC

Abstract

The question of whether the BEC is a necessary condition of the Meissner effect is examined. The electromagnetic susceptibility of a charged Bose gas with short-range repulsion is studied using the perturbation theory with respect to the repulsive force. With decreasing temperature, the Bose-statistical coherence grows, and prior to the BEC phase the susceptibility shows a singularity implying the Meissner effect. This means that the BEC is a sufficient, but not a necessary condition of the Meissner effect in the charged Bose gas with short-range repulsion.