Self-Consistent Field Theory studies of the thermodynamics and quantum spin dynamics of magnetic Skyrmions

Abstract

A self-consistent field theory is introduced and used to investigate the thermodynamics and spin dynamics of an $S = 1$ quantum spin system with a magnetic Skyrmion. The temperature dependence of the Skyrmion profile as well as the phase diagram are calculated. It is shown that the Skyrmion carries a phase transition to the ferromagnetic phase of first order with increasing temperature, while the magnetization of the surrounding ferromagnet undergoes a phase transition of second order when changing to the paramagnetic phase. Furthermore, the electric field driven annihilation process of the Skyrmion is described quantum mechanical by solving the time dependent Schr\"odinger equation. The results are compared with the trajectories of the semi-classical description of the spin expectation values using a differential equation similar to the classical Landau-Lifshitz-Gilbert equation.