Abstract
An upper bound is derived for the tunneling rate of a spin with large spin quantum numberS. The bound isuniversal in the sense that it does not depend on the specific form of the anisotropy (i.e., the potential barrier). The method of proof relies on the exponential localization theorem of Fröhlich and Lieb and lends precise support to a rather suggestive interpretation put forth in a WKB analysis of van Hemmen and Sütő. The resulting bound agrees with their expression for the tunneling rate in the limit of largeS.
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Communicated by B. Simon
Supported in part by the Conselho Nacional de Desenvolvimento Cientifico e Technológico (CNPq)
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van Hemmen, J.L., Wreszinski, W.F. Universal upper bound for the tunneling rate of a large quantum spin. Commun.Math. Phys. 119, 213–219 (1988). https://doi.org/10.1007/BF01217739
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DOI: https://doi.org/10.1007/BF01217739