Antimagnonics

TL;DR

This paper introduces antimagnons as the antiparticles of magnons, exploring their stability, thermal behavior, and implications for advanced magnonic phenomena and spintronic applications.

Contribution

It presents the concept of antimagnons, analyzes their stability and thermal properties, and connects them to phenomena like the Klein effect and black-hole analogs in magnonics.

Findings

Antimagnons can be stable excitations in magnetic systems.

Thermal occupation of antimagnons influences magnonic behaviors.

The concept unifies understanding of magnonic Klein effect and black-hole analogs.

Abstract

Magnons are the quanta of collective spin excitations in magnetically-ordered systems and manipulation of magnons for computing and information processing has witnessed the development of ``magnonics". A magnon corresponds to an excitation of the magnetic system from its ground state and the creation of a magnon thus increases the total energy of the system. In this perspective, we introduce the antiparticle of a magnon, dubbed the antimagnon, as an excitation that lowers the magnetic energy. We investigate the stability and thermal occupation of antimagnons and verify our theory by micromagnetic simulations. Furthermore, we show how the concept of antimagnons yields a unified picture to understand the magnonic analog of the Klein effect, magnonic black-hole horizons, and magnonic black-hole lasing. Our work may stimulate fundamental interest in antimagnons, as well as their applications to spintronic devices.