Quantum-classical transition of the escape rate of a biaxial spin system in a general magnetic field

Abstract

Using the method of mapping of a spin problem onto a particle one, we study phase transition between quantum and classical regimes for the escape rate of biaxial spin system in the presence of both a transverse and longitudinal field. It is found that the phase diagram separating the first- from the second-order transition and its crossover temperature are greatly influenced by the ratio of the anisotropy constants as well as the external magnetic field via the particle mass and the potential.