Surface-induced reduction of the switching field in nanomagnets

TL;DR

This study demonstrates that surface anisotropy-induced spin-misalignment in nanomagnets can lower the magnetic switching field when subjected to combined RF and DC magnetic fields, enhancing understanding of magnetization reversal.

Contribution

It introduces a numerical analysis showing how surface anisotropy influences magnetization switching in nanomagnets under RF and DC fields.

Findings

Surface anisotropy induces spin-misalignment.

Switching occurs at weaker fields than Stoner-Wohlfarth prediction.

Optimal RF field parameters enhance switching efficiency.

Abstract

Magnetization reversal in a many-spin nanomagnet subjected to an rf magnetic field, on top of a DC magnetic field, is studied by numerically solving the system of coupled (damped) Landau-Lifshitz equations. It is demonstrated that spin-misalignment induced by surface anisotropy favors switching with a DC magnetic field weaker than the Stoner-Wohlfarth switching field, for optimal intensities and frequencies of the rf field.