Thermally excited spin waves in a nano-structure: thermal gradient vs. constant temperature

TL;DR

This study uses micromagnetic simulations to explore how thermal fluctuations, including uniform temperature and thermal gradients, influence spin wave dynamics in nanostructures, highlighting the damping parameter's role in wave amplification.

Contribution

It demonstrates the impact of thermal fluctuations and gradients on spin dynamics and identifies the Gilbert damping parameter as a control for spin wave amplification.

Findings

Thermal fluctuations increase magnetization precession angles.

Resonance linewidths decrease mildly under thermal effects.

Gilbert damping controls spin wave amplification.

Abstract

Using micromagnetic simulations, we have investigated spin dynamics in a nanostructure in the presence of thermal fluctuations. In particular, we have studied the effects of a uniform temperature and of a uniform thermal gradient. In both cases, the stochastic field leads to an increase of the precession angle of the magnetization, and to a mild decreas of the linewidth of the resonance peaks. Our results indicate that the Gilbert damping parameter plays the role of control parameter for the amplification of spin waves.