Quantum coherence in biaxial nanomagnets with a large transverse magnetic field

Abstract

We study quantum coherence of the biaxial spin system with a large magnetic field along an arbitrary direction in the plane of hard and medium axes. Within the framework of the instanton method we present the analytic formula of the oscillation rate as a function of magnitude and direction of the magnetic field, and discuss its thermal effect. These features are expected to be tested in existing experimental techniques.