Superconducting properties of MgB2 from first principles

TL;DR

This paper applies a new density-functional theory for superconductors to MgB2, accurately predicting its superconducting properties without adjustable parameters and revealing the Coulomb interaction's role in stabilizing its phase.

Contribution

First non-trivial application of a novel density-functional-type theory to MgB2, achieving accurate predictions of superconducting properties without adjustable parameters.

Findings

Transition temperature and gaps match experimental data

Coulomb interaction stabilizes the superconducting phase

Method provides insights into electron interactions in MgB2

Abstract

Solid MgB$_2$ has rather interesting and technologically important properties, such as a very high superconducting transition temperature. Focusing on this compound, we report the first non-trivial application of a novel density-functional-type theory for superconductors, recently proposed by the authors. Without invoking any adjustable parameters, we obtain the transition temperature, the gaps, and the specific heat of MgB$_2$ in very good agreement with experiment. Moreover, our calculations show how the Coulomb interaction acts differently on s and p states, thereby stabilizing the observed superconducting phase.