Specific Heat of Disordered Superconductors Induced by Negative Centers

TL;DR

This paper investigates how disorder from randomly distributed attractive centers in superconductors alters the low-temperature specific heat from exponential to power-law behavior, using a random negative U Hubbard model and CPA.

Contribution

It introduces a model for disordered superconductors with inhomogeneous order parameters and analyzes their specific heat behavior at low temperatures.

Findings

Disorder converts exponential specific heat dependence into a power law.

Superconductors with inhomogeneous order parameters exhibit similar features as anisotropic ones.

The study uses a random negative U Hubbard model with CPA to describe the system.

Abstract

We show that superconductors with inhomogeneous order parameters can show similar features as anisotropic ones. In this paper we study the low temperature specific heat dependence in such a system and we show that the disorder associated with randomly distributed attractive centers convert the BCS temperature exponential behaviour into a power law formula. To describe superconductivity we used a random version of the negative U Hubbard model, while the disorder was treated by means of the Coherent Potential Approximation (CPA).