Spirals and skyrmions in two dimensional oxide heterostructures

TL;DR

This paper develops a comprehensive free energy model for magnetism in 2D oxide heterostructures, revealing a rich phase diagram with various magnetic and nematic phases influenced by spin-orbit coupling.

Contribution

It introduces a universal free energy framework applicable to diverse mechanisms of magnetism in 2D oxides, predicting multiple complex magnetic phases.

Findings

Identification of in-plane ferromagnetic, spiral, cone, and skyrmion lattice phases.

Prediction of a nematic state stabilized by thermal fluctuations.

Validation of the model through a microscopic derivation with Rashba spin-orbit coupling.

Abstract

We construct the general free energy governing long-wavelength magnetism in two-dimensional oxide heterostructures, which applies irrespective of the microscopic mechanism for magnetism. This leads, in the relevant regime of weak but non-negligible spin-orbit coupling, to a rich phase diagram containing in-plane ferromagnetic, spiral, cone, and skyrmion lattice phases, as well as a nematic state stabilized by thermal fluctuations. The general conclusions are vetted by a microscopic derivation for a simple model with Rashba spin-orbit coupling.