How the Phase Slips in a Current-Biased Narrow Superconducting Stripe?

TL;DR

This paper revisits the theory of current transport in narrow superconducting channels, analyzing thermal fluctuations and vortex crossings to understand voltage behavior near the critical temperature and current.

Contribution

It provides a detailed analysis of vortex crossing effects, showing an increased activation energy for phase slips in narrow superconducting stripes.

Findings

Voltage depends on temperature and bias current near $T_c$

Vortex crossing significantly increases activation energy

Thermal fluctuations influence current transport behavior

Abstract

The theory of current transport in a narrow superconducting channel accounting for thermal fluctuations is revisited. The value of voltage appearing in the sample is found as the function of temperature (close to transition temperature $T-T_{\mathrm{c}}$ $\ll T_{\mathrm{c}}$) and bias current $J<J_{\mathrm{c}}$ ( $J_{\mathrm{c}}$ is a value of critical current calculated in the framework of the BCS approximation, neglecting thermal fluctuations). It is shown that the careful analysis of vortex crossing of the stripe results in considerable increase of the activation energy.