Non-Hermitian skin effect in magnetic systems

TL;DR

This paper explores the non-Hermitian skin effect in magnetic insulators, showing how magnetic dissipation and Dzyaloshinskii-Moriya interactions lead to boundary localization of bulk states in a specific temperature range.

Contribution

It introduces a phenomenological model for magnetic dissipation and demonstrates the emergence of the skin effect in a spin-orbit-coupled ferromagnet with magnon-phonon interactions.

Findings

Magnetic skin effect appears at certain temperatures.

Interference between DMI and magnetic dissipation causes boundary localization.

The model explains bulk-boundary behavior in magnetic systems.

Abstract

Far from being limited to a trivial generalization of their Hermitian counterparts, non-Hermitian topological phases have gained widespread interest due to their unique properties. One of the most striking non-Hermitian phenomena is the skin effect, i.e., the localization of a macroscopic fraction of bulk eigenstates at a boundary, which underlies the breakdown of the bulk-edge correspondence. Here we investigate the emergence of the skin effect in magnetic insulating systems by developing a phenomenological approach to describing magnetic dissipation within a lattice model. Focusing on a spin-orbit-coupled van der Waals (vdW) ferromagnet with spin-nonconserving magnon-phonon interactions, we find that the magnetic skin effect emerges in an appropriate temperature regime. Our results suggest that the interference between Dzyaloshinskii-Moriya interaction (DMI) and nonlocal magnetic dissipation plays a key role in the accumulation of bulk states at the boundaries.