Spin-Mechanical Inertia in Antiferromagnet

TL;DR

This paper reveals how antiferromagnetic spin dynamics influence mechanical inertia, showing that Neel order affects a body's inertia tensor, with effects depending on temperature and magnon excitations, leading to potential measurable small-scale phenomena.

Contribution

It introduces the concept of spin-mechanical inertia in antiferromagnets and explains how Neel order modifies inertia tensor considering temperature and magnon effects.

Findings

Neel order dynamics alter the inertia tensor of a rigid body.

Spin-mechanical inertia depends on temperature and magnon excitations.

Potential measurable effects at small scales due to this inertia modification.

Abstract

Angular momentum conservation has served as a guiding principle in the interplay between spin dynamics and mechanical rotations. However, in an antiferromagnet with vanishing magnetization, new fundamental rules are required to properly describe spin-mechanical phenomena. Here we show that the N\'eel order dynamics affects the mechanical motion of a rigid body by modifying its inertia tensor in the presence of strong magnetocrystalline anisotropy. This effect depends on temperature when magnon excitations are considered. Such a spin-mechanical inertia can produce measurable consequences at small scales.