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Evidence for Thermally Activated Spontaneous Fluxoid Formation in Superconducting Thin-Film Rings

J. R. Kirtley·C. C. Tsuei·F. Tafuri
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Abstract

We have observed spontaneous fluxoid generation in thin-film rings of the amorphous superconductor Mo$_3$Si, cooled through the normal-superconducting transition, as a function of quench rate and externally applied magnetic field, using a variable sample temperature scanning SQUID microscope. Our results can be explained using a model of freezout of thermally activated fluxoids, mediated by the transport of bulk vortices across the ring walls. This mechanism is complementary to a mechanism proposed by Kibble and Zurek, which only relies on causality to produce a freezout of order parameter fluctuations.

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J. R. Kirtley, C. C. Tsuei, F. Tafuri. 2003-02-19. Evidence for Thermally Activated Spontaneous Fluxoid Formation in Superconducting Thin-Film Rings. https://doi.org/10.1103/physrevlett.90.257001

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