# Theoretical models of Rashba spin splitting in asymmetric SrTiO3-based heterostructures

## TL;DR

This paper compares two theoretical approaches to Rashba spin splitting in SrTiO3-based heterostructures, emphasizing the importance of choosing the correct model for interpreting experimental data in correlated 2D systems.

## Contribution

It demonstrates fundamental differences between band structure and phenomenological models for Rashba splitting in correlated 2D electron systems.

## Key findings

- Different models predict distinct behaviors in key Brillouin zone regions.
- Correct model choice is crucial for accurate experimental data interpretation.
- Results are relevant for various correlated 2D materials.

## Abstract

Rashba spin splitting in two-dimensional (2D) semiconductor systems is generally calculated in a ${\bf k} \cdot {\bf p}$ Luttinger-Kohn approach where the spin splitting due to asymmetry emerges naturally from the bulk band structure. In recent years, several new classes of 2D systems have been discovered where electronic correlations are believed to have an important role. In these correlated systems, the effects of asymmetry leading to Rashba splitting have typically been treated phenomenologically. We compare these two approaches for the case of 2D electron systems in SrTiO$_3$-based heterostructures, and find that the two models produce fundamentally different behavior in regions of the Brillouin zone that are particularly relevant for magnetotransport. Our results demonstrate the importance of identifying the correct approach in the quantitative interpretation of experimental data, and are likely to be relevant to a range of 2D systems in correlated materials.