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Quantum nucleation in ferromagnets with tetragonal and hexagonal symmetries

Yi Zhou·Rong Lu·Jia-Lin Zhu·Lee Chang
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Abstract

The phenomenon of quantum nucleation is studied in a ferromagnet in the presence of a magnetic field at an arbitrary angle. We consider the magnetocrystalline anisotropy with tetragonal symmetry and that with hexagonal symmetry, respectively. By applying the instanton method in the spin-coherent-state path-integral representation, we calculate the dependence of the rate of quantum nucleation and the crossover temperature on the orientation and strength of the field for a thin film and for a bulk solid. Our results show that the rate of quantum nucleation and the crossover temperature depend on the orientation of the external magnetic field distinctly, which provides a possible experimental test for quantum nucleation in nanometer-scale ferromagnets.

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Yi Zhou, Rong Lu, Jia-Lin Zhu, Lee Chang. 2000-11-09. Quantum nucleation in ferromagnets with tetragonal and hexagonal symmetries. https://doi.org/10.1103/physrevb.63.054429

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