Strong spin-orbit coupling effects on the Fermi surface of Sr2RuO4 and Sr2RhO4

TL;DR

This study uses first-principles calculations to reveal how spin-orbit coupling significantly alters the Fermi surfaces of Sr2RuO4 and Sr2RhO4, impacting their electronic properties and understanding of superconductivity.

Contribution

It provides a detailed analysis of spin-orbit effects on Fermi surfaces, highlighting their importance in accurately modeling these materials.

Findings

Spin-orbit coupling dramatically changes the Fermi surface in Sr2RhO4.

Subtle but significant Fermi surface modifications in Sr2RuO4 due to spin-orbit coupling.

Strong momentum dependence of electronic states normal to RuO2 planes.

Abstract

We present a first-principle study of spin-orbit coupling effects on the Fermi surface of Sr2RuO4 and Sr2RhO4. For nearly degenerate bands, spin-orbit coupling leads to a dramatic change of the Fermi surface with respect to non-relativistic calculations; as evidenced by the comparison with experiments on Sr2RhO4, it cannot be disregarded. For Sr2RuO4, the Fermi surface modifications are more subtle but equally dramatic in the detail: spin-orbit coupling induces a strong momentum dependence, normal to the RuO2 planes, for both orbital and spin character of the low-energy electronic states. These findings have profound implications for the understanding of unconventional superconductivity in Sr2RuO4.