Inertial spin waves in ferromagnets and antiferromagnets

TL;DR

This paper theoretically investigates inertial effects in spin dynamics of ferromagnets and antiferromagnets, revealing how inertial effects modify spin-wave properties and proposing methods to distinguish these effects experimentally.

Contribution

It provides a detailed calculation of the spin-wave spectrum incorporating inertial effects, highlighting the hybridization of precession and nutation spin waves and their impact on key parameters.

Findings

Inertial effects cause hybridization of precession and nutation spin waves.

Inertial effects lead to renormalization of frequencies, group velocities, and damping.

Proposes experimental signatures to distinguish inertial effects from conventional models.

Abstract

Inertial effects in spin dynamics are theoretically predicted to emerge at ultrashort time scales, but their experimental signatures are often ambiguous. Here, we calculate the spin-wave spectrum in ferromagnets and two-sublattice antiferromagnets in the presence of inertial effects. It is shown how precession and nutation spin waves hybridize with each other, leading to the renormalization of the frequencies, the group velocities, the effective gyromagnetic ratios and the effective damping parameters. Possible ways of distinguishing between the signatures of inertial dynamics and similar effects explainable within conventional models are discussed.