Magnetization quantum tunneling at excited levels for a biaxial spin system in an arbitrarily directed magnetic field

TL;DR

This paper theoretically investigates quantum tunneling of magnetization at excited levels in biaxial ferromagnetic nanoparticles under arbitrary magnetic field directions, analyzing temperature effects on tunneling frequency and decay rate.

Contribution

It introduces a theoretical framework for understanding magnetization tunneling at excited states in biaxial systems with arbitrary magnetic field orientations.

Findings

Temperature influences tunneling frequency and decay rate.

Tunneling behavior varies with magnetic field direction.

Excited level tunneling is significant in nanoparticle magnetization dynamics.

Abstract

The quantum tunneling of the magnetization vector between excited levels are studied theoretically in single-domain ferromagnetic nanoparticles with biaxial crystal symmetry placed in an external magnetic field at an arbitarily directed angle in the ZX plane. The temperature dependences of the tunneling frequency and the decay rate are clearly shown for each case.