Masking effect of heat dissipation on the current-voltage characteristics of a mesoscopic superconducting square with leads

TL;DR

This paper presents a theoretical study demonstrating how heat dissipation affects the current-voltage behavior of a mesoscopic superconducting square, revealing hysteresis and nonmonotonous switching currents influenced by magnetic fields.

Contribution

It introduces a numerical model combining Ginzburg-Landau and heat equations to explain heat dissipation effects on superconducting transport properties, aligning with experimental observations.

Findings

Heat dissipation increases hysteresis in I-V characteristics.

Switching current depends nonmonotonously on magnetic field due to vorticity changes.

Heat masking affects the interpretation of superconducting dynamics.

Abstract

A theoretical analysis based on a numerical solution of the coupled time-dependent Ginzburg-Landau and heat dissipation equations shows a strong dependence of the critical currents on the applied magnetic field in a mesoscopic square with attached contacts. In agreement with experiment we found hysteresis which are caused by a strong heat dissipation in the sample at currents close to the depairing Ginzburg-Landau current and/or the dynamics of the superconducting condensate. The theoretically obtained nonmonotonous dependence of the switching current (from superconducting to the resistive state) on the applied magnetic field, arising from the changes in the vorticity, agrees quantitatively with the experimental data. Our results show that heat dissipation leads to an increase of the hysteresis in the current-voltage characteristic and hence masks the actual dynamics of the superconducting condensate.