Comment on: Superfluid density and specific heat within a self-consistent scheme for a two-band superconductor

TL;DR

This paper critiques a previous two-band superconductor model, highlighting its simplifications and unphysical assumptions that lead to incorrect results on properties like superfluid density and specific heat.

Contribution

It provides a critical analysis of the existing model, clarifying its limitations and correcting misconceptions about two-band superconductor properties.

Findings

The original model contains simplifications that lead to unphysical results.

Erroneous conclusions were drawn about the dependence of Tc on model parameters.

The critique clarifies the correct interpretation of superfluid density and specific heat in two-band superconductors.

Abstract

Kogan et al. [Phys. Rev. B 80, 014507 (2009)] present a two-band model to investigate its effect on superconducting properties as, e.g., the superfluid density, the specific heat, the dependence of the superconducting transition temperature Tc on the model parameters. Due to a variety of simplifications and unphysical consequences of those, erroneous results and misleading conclusions are obtained.