Nonlinear Dynamics of Quasiclassical Spin Moment in a Swept Field

Quantum dynamics of anisotropic spin system with large spin moment in a swept magnetic field is theoretically investigated. Magnetic field of this type induces vortex static electrical field, that breaks down the axial symmetry and induces new coherent quantum phenomena: the occurrence of band energy spectrum with continuous spin states, Bloch-type oscillations and interband Zener tunnelling effect. These quantum phenomena display themselves, in particular, in magnetization jumps and susceptibility peaks in the investigated spin system.