Magnonic black holes

TL;DR

This paper demonstrates that spin-polarized currents can create black-hole and white-hole horizons for magnons in various magnetic systems, potentially enabling new experiments in magnonics and quantum information.

Contribution

It introduces the concept of magnonic horizons using spin currents in different magnetic materials, a novel approach in magnonics.

Findings

Hawking temperature can reach up to 1 K based on experimental data.

Magnonic horizons affect spin-wave scattering and transport.

Potential implications for magnon entanglement and quantum information.

Abstract

We show that the interaction between spin-polarized current and magnetization dynamics can be used to implement black-hole and white-hole horizons for magnons - the quanta of oscillations in the magnetization direction in magnets. We consider three different systems: easy-plane ferromagnetic metals, isotropic antiferromagnetic metals, and easy-plane magnetic insulators. Based on available experimental data, we estimate that the Hawking temperature can be as large as 1 K. We comment on the implications of magnonic horizons for spin-wave scattering and transport experiments, and for magnon entanglement.