A pair potential supporting a mixed mean-field / BCS- phase

TL;DR

This paper introduces a Hamiltonian model that supports simultaneous mean-field and superconducting phases, revealing complex interactions where mean-field effects can either promote or inhibit superconductivity.

Contribution

The work constructs a Hamiltonian that in a scaling limit supports both mean-field and BCS-like phases, exploring their mutual influence.

Findings

Attractive mean field can enhance superconductivity

Repulsive mean field can suppress superconductivity

The model demonstrates complex interplay between phases

Abstract

We construct a Hamiltonian which in a scaling limit becomes equivalent to one that can be diagonalized by a Bogoliubov transformation. There may appear simultaneously a mean-field and a superconducting phase. They influence each other in a complicated way. For instance, an attractive mean field may stimulate the superconducting phase and a repulsive one may destroy it.