Spectral analysis of the precessional switching of the magnetization in an isotropic thin film

TL;DR

This paper analyzes the spectral properties of magnetization precessional switching in isotropic thin films, combining analytical and numerical methods to understand the dynamics and spectral purity of the magnetic response.

Contribution

It provides a simple analytical approach to estimate switching frequency and spectral characteristics, validated by numerical simulations, for isotropic thin film magnetization dynamics.

Findings

Analytical expressions for switching frequency are derived.

Magnetization components exhibit high spectral purity.

Periodic motions are well described by truncated Fourier expansions.

Abstract

We study how a magnetic field step triggers the precessional switching of the magnetization in an isotropic thin film . Using a variational approach, we estimate analytically the switching frequency and compare it to the results obtained numerically by direct integration of the equations of motion. We show that the periodic motions of the three magnetization components can be described satisfactorily with truncated Fourier expansions, indicating a relatively high spectral purity of the magnetic response. Our analytical expressions are simple enough to be physically transparent at first sight, in contrast to the results of the more elaborate models that treat also anisotropy.