Consistency of thermal activation model based on the stochastic Landau–Lifshitz equation and classical spin-wave description

Numerical studies of magnetisation fluctuations in a linear chain of spherical particles are carried out using the Langevin dynamic (LD) approach, and compared directly to the predictions of spin-wave theory. The results enable the identification of the magnetisation fluctuations in terms of exchange and magnetostatic spin-wave modes. Excellent quantitative agreement between the numerical and analytical results is obtained, suggesting that the LD approach correctly excites the normal modes (spin waves) of the chain.