Resonant suppression of thermal stability of the nanoparticle magnetization by a rotating magnetic field

TL;DR

This paper investigates how a rotating magnetic field affects the thermal stability of nanoparticle magnetization modes, revealing nonmonotonic lifetime behavior near the Larmor frequency through analytical and numerical methods.

Contribution

It introduces an analytical approach within the Fokker-Planck formalism to determine the lifetime of precessional modes under high anisotropy and small field amplitudes, complemented by numerical simulations.

Findings

Lifetime varies nonmonotonically with field frequency.

Maximum or minimum lifetime occurs near the Larmor frequency.

The direction of rotation influences stability behavior.

Abstract

We study the thermal stability of the periodic (P) and quasi-periodic (Q) precessional modes of the nanoparticle magnetic moment induced by a rotating magnetic field. An analytical method for determining the lifetime of the P mode in the case of high anisotropy barrier and small amplitudes of the rotating field is developed within the Fokker-Planck formalism. In general case, the thermal stability of both P and Q modes is investigated by numerical simulation of the stochastic Landau-Lifshitz equation. We show analytically and numerically that the lifetime is a nonmonotonic function of the rotating field frequency which, depending on the direction of field rotation, has either a pronounced maximum or a deep minimum near the Larmor frequency.