Thermal suppression of surface barrier in ultrasmall superconducting structures

W. V. Pogosov

doi:10.1103/physrevb.81.184517

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arXiv · 1009.0588

Thermal suppression of surface barrier in ultrasmall superconducting structures

W. V. Pogosov

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Abstract

In the recent experiment by Cren \textit{et al.} [Phys. Rev. Lett. \textbf{102}, 127005 (2009)], no hysteresis for vortex penetration and expulsion from the nano-island of Pb was observed. In the present paper, we argue that this effect can be associated with the thermoactivated surmounting of the surface barrier by a vortex. The typical entrance (exit) time is found analytically from the Fokker-Planck equation, written in the form suitable for the extreme vortex confinement. We show that this time is several orders of magnitude smaller than 1 second under the conditions of the experiment considered. Our results thus demonstrate a possibility for the thermal suppression of the surface barrier in nanosized low-$T_{c}$ superconductors. We also briefly discuss other recent experiments on vortices in related structures.

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W. V. Pogosov. 2010-09-03. Thermal suppression of surface barrier in ultrasmall superconducting structures. https://doi.org/10.1103/physrevb.81.184517

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