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Non-quantized Dirac monopoles and strings in the Berry phase of anisotropic spin systems

Patrick Bruno
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Abstract

The Berry phase of an anisotropic spin system that is adiabatically rotated along a closed circuit C is investigated. It is shown that the Berry phase consists of two contributions: (i) a geometric contribution which can be interpreted as the flux through C of a non-quantized Dirac monopole, and (ii) a topological contribution which can be interpreted as the flux through C of a Dirac string carrying a non-quantized flux, i.e., a spin analogue of the Aharonov-Bohm effect. Various experimental consequences of this novel effect are discussed.

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Patrick Bruno. 2004-08-31. Non-quantized Dirac monopoles and strings in the Berry phase of anisotropic spin systems. https://doi.org/10.1103/physrevlett.93.247202

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