The effect of confinement on thermal fluctuations in nanomagnets

Applied Physics Letters, Volume 118, Issue 14, April 2021. We study the magnetization dynamics in nanomagnets excited by stochastic magnetic fields to mimic temperature in a micromagnetic framework. The effect of confinement arising from the finite size of the structures is investigated, and we visualize the spatial extension of the internal magnon modes. Furthermore, we determine the temperature dependence of the magnon modes and focus specifically on the low frequency edge modes, which are found to display fluctuations associated with switching between C- and S-states, thus posing an energy barrier. We classify this fluctuating behavior in three different regimes and calculate the associated energy barriers using the Arrhenius law.