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Phase slips in superconducting films with constrictions

Sang L. Chu·A. T. Bollinger·A. Bezryadin
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Abstract

A system of two coplanar superconducting films seamlessly connected by a bridge is studied. We observe two distinct resistive transitions as the temperature is reduced. The first one, occurring in the films, shows some properties of the Berezinskii-Kosterlitz-Thouless (BKT) transition. The second apparent transition (which is in fact a crossover) is related to freezing out of thermally activated phase slips (TAPS) localized on the bridge. We also propose a powerful indirect experimental method allowing an extraction of the sample's zero-bias resistance from high-current-bias measurements. Using direct and indirect measurements, we determined the resistance $R(T)$ of the bridges within a range of {\em eleven orders of magnitude}. Over such broad range, the resistance follows a simple relation $R(T)=R_N \text{exp} [-(c/t)(1-t)^{3/2}]$, where $c=ΔF(0) / kT_c$ is the normalized free energy of a phase slip at zero temperature, $t=T/T_c$ is normalized temperature, and $R_N$ is the normal resistance of the bridge.

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Sang L. Chu, A. T. Bollinger, A. Bezryadin. 2004-11-08. Phase slips in superconducting films with constrictions. https://doi.org/10.1103/physrevb.70.214506

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