Texture fluctuations and emergent dynamics in coupled nanomagnets

TL;DR

This paper investigates how thermal fluctuations influence magnetization textures in coupled nanomagnets, revealing how energy barriers and coupling modify their dynamic behavior and fluctuation mechanisms.

Contribution

It provides a detailed analysis of the energy landscape and fluctuation dynamics in coupled nanomagnets, highlighting the effects of gap variation and edge coupling on their behavior.

Findings

Asymmetric energy barriers depend on the gap between mesospins.

Coupling induces anisotropy in energy surface curvature.

Edge magnon modes influence stochastic magnetization fluctuations.

Abstract

We analyse the thermal fluctuations of magnetization textures in two stray field coupled elements, forming mesospins. To this end, the energy landscape associated with the thermal dynamics of the textures is mapped out and asymmetric energy barriers are identified. These barriers are modified by changing the gap that separates the mesospins. Moreover, the coupling between the edges leads to an anisotropy in the curvature of the energy surface at the metastable minima. This yields a dynamic mode splitting of the edge modes and affects the attempt switching frequencies. Thus, we elucidate the mechanism with which the magnons in the thermal bath generate the stochastic fluctuations of the magnetization at the edges.