Spin-orbit coupling effects on the electronic properties of the pressure-induced superconductor CrAs

TL;DR

This study investigates how spin-orbit coupling influences the electronic structure and Fermi surface of the pressure-induced superconductor CrAs, revealing that Cr contributions are dominant and that spin-orbit effects can alter band degeneracies and Fermi surface topology.

Contribution

It provides a detailed analysis of spin-orbit effects on CrAs's electronic properties, highlighting the dominant role of Cr electrons and the impact on band degeneracies and Fermi surface reconstruction.

Findings

Cr contributions dominate spin-orbit effects

Spin-orbit coupling lifts band degeneracies

Fermi surface topology can change with spin-orbit interactions

Abstract

We present the effects of spin-orbit coupling on the low-energy bands and Fermi surface of the recently discovered pressure-induced superconductor CrAs. We apply the L\"owdin down-folding procedure to a tight-binding hamiltonian that includes the intrinsic spin-orbit interaction, originating from the Cr 3d electrons as well as from As 4p ones. Our results indicate that As contributions have negligible effects, whereas the modifications to the band structure and the Fermi surface can be mainly ascribed to the Cr contribution. We show that the inclusion of the spin-orbit interaction allows for a selective removal of the band degeneracy due to the crystal symmetries, along specific high symmetry lines. Such release of the band degeneracy naturally determines a reconstruction of the Fermi surface, including the possibility of changing the number of pockets.