Fermi surface and quasiparticle excitations of Sr$_{2}$RhO$_{4}$

TL;DR

This study uses angle-resolved photoemission to reveal the electronic structure of Sr$_{2}$RhO$_{4}$, showing a quasi-two-dimensional Fermi liquid state with specific band contributions, contrasting with theoretical predictions.

Contribution

First detailed experimental investigation of Sr$_{2}$RhO$_{4}$'s electronic structure highlighting discrepancies with density functional theory.

Findings

Quasiparticle excitations are well-defined with anisotropic dispersion.

Only two bands with Rh 4$d_{xz,zy}$ contribute to the Fermi surface.

Experimental data aligns with bulk measurements but not with local density approximation calculations.

Abstract

The electronic structure of the layered 4$d$ transition metal oxide Sr$_{2}$RhO$_{4}$ is investigated by angle resolved photoemission. We find well-defined quasiparticle excitations with a highly anisotropic dispersion, suggesting a quasi-two-dimensional Fermi liquid like ground state. Markedly different from the isostructural Sr$_{2}$RuO$_{4}$, only two bands with dominant Rh 4$d_{xz,zy}$ character contribute to the Fermi surface. A quantitative analysis of the photoemission quasiparticle band structure is in excellent agreement with bulk data. In contrast, it is found that state-of-the-art density functional calculations in the local density approximation differ significantly from the experimental findings.