Laser-induced antiferromagnetic-like resonance in amorphous ferrimagnets

TL;DR

This study demonstrates laser-induced antiferromagnetic-like resonance in amorphous ferrimagnets, revealing how magnetization precession modes change with laser fluence and magnetic field, aligning with theoretical models.

Contribution

It provides the first experimental demonstration of laser-induced antiferromagnetic resonance in amorphous ferrimagnets near the angular momentum compensation temperature.

Findings

Precession frequency decreases with magnetic field at low fluence.

Precession frequency increases with magnetic field at high fluence.

Data agrees with theoretical simulation of precession modes.

Abstract

The magnetization dynamics for ferrimagnets at the angular momentum compensation temperature T_A is believed to be analogous to that for antiferromagnets. We investigated the pulsed-laser-induced magnetization dynamics in amorphous rare-earth transition-metal ferrimagnet films with a T_A just above room temperature. For a low pulse fluence, the magnetization precession frequency decreases as the applied magnetic field increases, whereas for a higher pulse fluence, it increases as the applied field increases. The result was well explained by the left-handed and right-handed precession modes of the antiferromagnetic-like resonance at temperatures below and above T_A, respectively, and the data were in agreement with the theoretical simulation. The study demonstrated the experimental route to achieving antiferromagnetic resonance in ferrimagnets using a pulsed laser.