# Photoemission and Dynamical Mean Field Theory Study of Electronic Correlation in a $t_{2g}^{5}$ Metal of SrRhO$_{3}$ Thin Film

## TL;DR

This study investigates the electronic correlation and magnetic properties of SrRhO₃ thin films using photoemission spectroscopy and advanced theoretical calculations, revealing discrepancies between experimental observations and theoretical predictions regarding metallicity and magnetic behavior.

## Contribution

The paper combines experimental and theoretical approaches to clarify the electronic structure and correlation effects in SrRhO₃ thin films, highlighting the limited role of spin-orbit coupling.

## Key findings

- Experimental DOS at Fermi level is very small and persists up to room temperature.
- Theoretical calculations indicate metallic behavior and stronger correlations in thin films.
- Spin-orbit coupling has a moderate effect and is not crucial for electronic correlation.

## Abstract

Perovskite rhodates are characterized by intermediate strengths of both electronic correlation as well as spin-orbit coupling (SOC) and usually behave as moderately correlated metals. A recent publication (Phys. Rev. B 95, 245121(2017)) on epitaxial SrRhO$_3$ thin films unexpectedly reported a bad-metallic behavior and suggested the occurrence of antiferromagnetism below 100 K. We studied this SrRhO$_3$ thin film by hard x-ray photoemission spectroscopy and found a very small density of states (DOS) at Fermi level, which is consistent with the reported bad-metallic behavior. However, this negligible DOS persists up to room temperature, which contradicts with the explanation of antiferromagnetic transition at around 100 K. We also employed electronic structure calculations within the framework of density functional theory and dynamical mean-field theory. In contrast to the experimental results, our calculations indicate metallic behavior of both bulk SrRhO$_3$ and the SrRhO$_3$ thin film. The thin film exhibits stronger correlation effects than the bulk, but the correlation effects are not sufficient to drive a transition to an insulating state. The calculated uniform magnetic susceptibility is substantially larger in the thin film than that in the bulk. The role of SOC was also investigated and only a moderate modulation of the electronic structure was observed. Hence SOC is not expected to play an important role for electronic correlation in SrRhO$_3$.