Coulomb-Enhanced Spin-Orbit Splitting: The Missing Piece in the Sr2RhO4 Puzzle

TL;DR

This paper resolves the discrepancy in Sr2RhO4's Fermi surface calculations by incorporating Coulomb repulsion and spin-orbit coupling, revealing an enhanced effective spin-orbit interaction and aligning theoretical predictions with experimental data.

Contribution

It introduces a formalism that combines Coulomb repulsion with spin-orbit coupling, explaining the Fermi surface and thermodynamic properties of Sr2RhO4.

Findings

Effective spin-orbit coupling is enhanced 2.15 times over the bare value.

The experimental specific-heat and mass enhancements are approximately 2.2.

The formalism can be applied to other similar systems.

Abstract

The outstanding discrepancy between the measured and calculated (local-density approximation) Fermi surfaces in the well-characterized, paramagnetic Fermi liquid Sr2RhO4 is resolved by including the spin-orbit coupling and Coulomb repulsion. This results in an effective spin-orbit coupling constant enhanced 2.15 times over the bare value. A simple formalism allows discussion of other systems. For Sr2RhO4, the experimental specific-heat and mass enhancements are found to be 2.2.