Activation of additional energy dissipation processes in the magnetization dynamics of epitaxial chromium dioxide films

TL;DR

This study investigates the magnetization dynamics in epitaxial chromium dioxide films, revealing how energy dissipation channels activate at certain thresholds, affecting damping behavior and potentially linked to spin-wave instabilities.

Contribution

It demonstrates the activation of additional energy dissipation processes in chromium dioxide films and highlights the influence of laser fluency on damping behavior.

Findings

Damping depends strongly on frequency and laser fluency.

Above a threshold fluency, energy dissipation channels activate.

Possible link to spin-wave instabilities.

Abstract

The precessional magnetization dynamics of a chromium dioxide$(100)$ film is examined in an all-optical pump-probe setup. The frequency dependence on the external field is used to extract the uniaxial in-plane anisotropy constant. The damping shows a strong dependence on the frequency, but also on the laser pump fluency, which is revealed as an important experiment parameter in this work: above a certain threshold further channels of energy dissipation open and the damping increases discontinuously. This behavior might stem from spin-wave instabilities.