Theory of coexistence of superconductivity and ferroelectricity

TL;DR

This paper investigates the coexistence and competition of ferroelectricity and superconductivity, providing exact solutions and mean-field analysis to understand their interplay and effects on order parameters.

Contribution

It offers an exact diagonalization of a Hamiltonian from prior work and introduces a new Hamiltonian with different coupling, analyzing their effects.

Findings

Exact diagonalization differs from mean-field results

Coupling significantly influences order parameters

New Hamiltonian alters coexistence conditions

Abstract

A new investigation of the coexistence and competition of ferroelectricity and superconductivity is reported. In particular we show that the starting Hamiltonian of a previous study by Birman and Weger (2001) can be exactly diagonalized. The result differs significantly from mean-field theory. A Hamiltonian with a different realization of the coupling between ferroelectricity and superconductivity is proposed. We report the results for mean-field theory applied to this Hamiltonian. We find that the order parameters are strongly affected by this coupling.