Interaction-Induced Enhancement of Spin-Orbit Coupling in Two-Dimensional Electronic System

TL;DR

This paper theoretically investigates how electron-electron interactions enhance spin-orbit coupling in two-dimensional electron systems, revealing a weaker but similar enhancement pattern to the g factor, with analytical and numerical evaluations across different interaction regimes.

Contribution

It provides the first comprehensive analysis of interaction-induced spin-orbit coupling enhancement, including analytical and numerical results for various electron densities.

Findings

Spin-orbit coupling is enhanced by electron-electron interactions.

The enhancement is weaker than that of the g factor.

Interaction effects on Zeeman splitting and spin-orbit coupling are interconnected.

Abstract

We study theoretically the renormalization of the spin-orbit coupling constant of two-dimensional electrons by electron-electron interactions. We demonstrate that, similarly to the $g$ factor, the renormalization corresponds to the enhancement, although the magnitude of the enhancement is weaker than that for the $g$ factor. For high electron concentrations (small interaction parameter $r_s$) the enhancement factor is evaluated analytically within the static random phase approximation. For large $r_s\sim 10$ we use an approximate expression for effective electron-electron interaction, which takes into account the local field factor, and calculate the enhancement numerically. We also study the interplay between the interaction-enhanced Zeeman splitting and interaction-enhanced spin-orbit coupling.