Perpendicular edge magnetization fluctuations in a double mesospin system

Elongated nanomagnets, ‘mesospins’, are used as building blocks in a range of mesoscopic spin systems in order to study, for example, frustrated physics and phase transitions in magnetic metamaterials. These mesospins are designed in such a way that shape anisotropy determines their effective spin dimesionality. Previously, we have performed a micromagnetic study of the effect of temperature on the internal texture of Ising-like mesospins, and found the excitation of thermal magnons along with the occurrence of stochastic switching of the magnetization at the edge of the nanomagnet. In this work, we explore in a micromagnetic framework the effects on the edge fluctuations when a second, oppositely magnetized Ising-like mesospin is added. We map out the energy landscape of this system and identify two different energy barriers, which are modified as the spacing between the mesospins is varied. We gather switching statistics for this system and obtain energy barriers and attempt frequencies via Arrhenius law. We find inverse scaling of the low energy barrier compared to the associated attempt frequency. Finally, we calculate the mode spectrum for this system and investigate the relevance of these magnon modes for the switching behavior.