ISSN:
1434-6036
Keywords:
PACS. 75.45.+j Macroscopic quantum phenomena in magnetic systems - 75.10.Jm Quantized spin models - 03.65.Bz Foundations, theory of measurement, miscellaneous theories (including Aharonov-Bohm effect, Bell inequalities, Berry's phase)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract. The quantum interference effects induced by the Wess-Zumino term, or Berry phase are studied theoretically in resonant quantum coherence of the magnetization vector between degenerate states in nanometer-scale single-domain ferromagnets in the absence of an external magnetic field. We consider the magnetocrystalline anisotropy with trigonal, tetragonal and hexagonal crystal symmetry, respectively. By applying the periodic instanton method in the spin-coherent-state path integral, we evaluate the low-lying tunnel splittings between degenerate excited states of neighboring wells. And the low-lying energy level spectrum of mth excited state are obtained with the help of the Bloch theorem in one-dimensional periodic potential. The energy level spectrum and the thermodynamic properties of magnetic tunneling states are found to depend significantly on the total spins of ferromagnets at sufficiently low temperatures. Possible relevance to experiments is also discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s100510070210
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