Superconductivity in non-centrosymmetric BiPd system

TL;DR

This paper confirms bulk superconductivity in high-quality monoclinic BiPd below 3.87 K, characterizing its properties and finding minimal influence of spin-orbit splitting on its superconducting behavior.

Contribution

It provides the first detailed study of the superconducting properties of non-centrosymmetric BiPd, including its electron-phonon coupling and the role of spin-orbit effects.

Findings

BiPd is a clean type-II superconductor with T_c of 3.87 K.

Spin-orbit splitting has little effect on its superconducting properties.

BiPd exhibits moderate electron-phonon coupling.

Abstract

In this work, we establish the bulk superconductivity of a high quality sample of monoclinic BiPd ($\alpha$-BiPd, space group P2$_1$) below 3.87 K by studying its electrical resistivity, magnetic susceptibility and heat capacity. We show that it is clean type-II superconductor with moderate electron-phonon coupling and determine its superconducitng and normal state parameters. Although $\alpha$-BiPd is a noncentrosymmetric superconductor with large electronic heat capacity (therefore, large $\gamma$), the effect of spin-orbit splitting of the electronic bands at the Fermi level is small. This makes little influence on the superconducting properties of $\alpha$-BiPd.