Unstable flux flow due to heated electrons in YBaCuO films

TL;DR

This paper investigates a flux instability in YBaCuO superconducting films caused by heated electrons, leading to non-monotonic current-voltage behavior and vortex expansion, supported by experimental measurements.

Contribution

It introduces a new mechanism for flux instability driven by electron heating and demonstrates its validity through quantitative agreement with experiments.

Findings

Flux instability occurs at low temperatures due to electron heating.

The vortex expands, contrasting with previous models.

Experimental data in YBaCuO supports the proposed mechanism.

Abstract

A flux instability occurs in superconductors at low temperatures, where ee scattering is more rapid than ep, whereby the dissipation significantly elevates the electronic temperature while maintaining a thermal-like distribution function. The reduction in condensate and rise in resistivity produce a non-monotonic current-voltage response. In contrast to the Larkin-Ovchinnikov instability where the vortex shrinks, in this scenario the vortex expands and the quasiparticle population rises. Measurements in YBaCuO agree quantitatively with the distinct predictions of this mechanism.