Chiral and Topological Orbital Magnetism of Spin Textures

TL;DR

This paper reveals how chiral and topological orbital magnetism arise in two-dimensional spin textures, linking them to Berry curvature and emergent magnetic fields, with implications for orbitronics.

Contribution

It introduces a semiclassical Green's function approach to quantify orbital magnetism in spin textures, highlighting the role of Berry curvature without spin-orbit coupling.

Findings

Orbital magnetism is proportional to texture gradients.

Emergent magnetic fields explain orbital moments in absence of spin-orbit coupling.

Tuning parameters in surface systems can control emergent orbital magnetism.

Abstract

Using a semiclassical Green's function formalism, we discover the emergence of chiral and topological orbital magnetism in two-dimensional chiral spin textures by explicitly finding the corrections to the orbital magnetization, proportional to the powers of the gradients of the texture. We show that in the absence of spin-orbit coupling, the resulting orbital moment can be understood as the electronic response to the emergent magnetic field associated with the real-space Berry curvature. By referring to the Rashba model, we demonstrate that by tuning the parameters of surface systems the engineering of emergent orbital magnetism in spin textures can pave the way to novel concepts in orbitronics.