Theoretical investigation of electronic specific heat of two-band superconductors

TL;DR

This paper uses a generalized two-band model to accurately calculate the electronic specific heat, superconducting gaps, and coupling constants of MgB2 and Ba(Fe0.925Co0.075)2As2, matching experimental data.

Contribution

It introduces a generalized two-band model that improves the calculation of electronic specific heat in multi-band superconductors, especially for cleaner samples.

Findings

The model accurately describes the temperature dependence of specific heat.

Results align well with experimental data for MgB2 and Ba(Fe0.925Co0.075)2As2.

Comparison shows advantages over the traditional two-band model in certain regimes.

Abstract

We apply the generalized two-band model of superconductivity to calculate the electronic contribution to the specific heat, superconducting gaps and electron-boson coupling constants of the multi-band layered superconductors MgB2 and Ba(Fe0.925Co0.075)2As2. For both compounds, the obtained temperature-behavior of the specific heat well describes the experimental data. We compare our findings with the "two-band - model" that is frequently used to calculate the electronic specific heat, and that is applicable only for superconductors with strong interband scattering ("dirty" enough superconductors).