A computational method to estimate spin-orbital interaction strength in solid state systems

TL;DR

This paper introduces a computational approach combining ab initio and tight-binding calculations to accurately estimate spin-orbit coupling strength in solid state materials, facilitating better modeling of SOC-driven phenomena.

Contribution

The paper presents a simple, effective computational method to estimate on-site SOC strength, improving upon rough spectroscopic estimates and applicable to various materials.

Findings

Method shows high sensitivity and wide applicability.

Estimated SOC strengths agree with literature values.

Applicable to materials with different SOC active ions.

Abstract

Spin-orbit coupling (SOC) drives interesting and non-trivial phenomena in solid state physics, ranging from topological to magnetic to transport properties. Thorough study of such phenomena often require effective models where SOC term is explicitly included. However, estimation of SOC strength for such models mostly depend on the spectroscopy experiments which can only provide a rough estimate. In this work, we provide a simple yet effective computational approach to estimate the on-site SOC strength using a combination of the $ab$ $initio$ and tight-binding calculations. We demonstrate the wider applicability and high sensitivity of our method considering materials with varying SOC strengths and the number of SOC active ions. The estimated SOC strengths agree well with the proposed values in literature lending support to our methodology. This simplistic approach can readily be applied to a wide range of materials.