An attempt at a resonating mean-field theoretical description of thermal behavior of two-gap superconductivity

TL;DR

This paper extends the resonating mean-field theory to describe the thermal behavior of two-gap superconductivity, providing a new formula that predicts a higher critical temperature than traditional methods.

Contribution

It introduces a resonating mean-field theoretical framework for the thermal analysis of two-gap superconductors, improving upon existing models with a new formula for Tc.

Findings

Res-MF theory effectively describes two-gap superconductivity.

New formula predicts higher Tc than traditional HB formula.

Res-HB ground state nearly exhausts correlation energy.

Abstract

The resonating mean-field theory (Res-MFT) has been applied and shown to effectively describe two-gap superconductivity (SC). Particularly at T=0 using a suitable chemical potential, the two-gap SC in MgB2 has been well described by the Res-Hartree-Bogoliubov theory (Res-HBT). The Res-HB ground state generated with HB wave functions almost exhausts the ground-state correlation energy in all the correlation regimes. In this paper we make an attempt at a Res-MF theoretical description of thermal behavior of the two-gap SC. In an energy-gap case we find a new formula leading to a higher Tc than the Tc of the usual HB formula.