Spin-orbit mediated anisotropic spin interaction in interacting electron systems

TL;DR

This paper uncovers a new type of anisotropic spin-spin interaction mediated by spin-orbit coupling in strongly correlated electron systems, which does not rely on wave function overlap and is significant in Wigner crystal states.

Contribution

It introduces a novel spin-orbit mediated anisotropic interaction of the van der Waals type, expanding understanding of spin interactions beyond standard exchange mechanisms.

Findings

Identifies a spin-orbit mediated anisotropic spin-spin coupling.

Shows this interaction does not require wave function overlap.

Highlights the importance of this interaction in Wigner crystal states.

Abstract

We investigate interactions between spins of strongly correlated electrons subject to the spin-orbit interaction. Our main finding is that of a novel, spin-orbit mediated anisotropic spin-spin coupling of the van der Waals type. Unlike the standard exchange, this interaction does not require the wave functions to overlap. We argue that this ferromagnetic interaction is important in the Wigner crystal state where the exchange processes are severely suppressed. We also comment on the anisotropy of the exchange between spins mediated by the spin-orbital coupling.