Current-induced highly dissipative domains in high Tc thin films

TL;DR

This study investigates the formation of highly dissipative domains in high Tc superconducting thin films under high current densities, revealing phenomena analogous to phase-slip centers and their impact on superconductivity.

Contribution

It demonstrates the existence of non-hot-spot dissipative domains in high Tc films, extending the understanding of phase-slip phenomena beyond near Tc conditions.

Findings

Dissipative domains form at a critical current j*

These domains are not hot spots but resemble phase-slip centers

Propagation of domains can destroy superconductivity

Abstract

We have investigated the resistive response of high Tc thin films submitted to a high density of current. For this purpose, current pulses were applied into bridges made of Nd(1.15)Ba(1.85)Cu3O7 and Bi2Sr2CaCu2O8. By recording the time dependent voltage, we observe that at a certain critical current j*, a highly dissipative domain develops somewhere along the bridge. The successive formation of these domains produces stepped I-V characteristics. We present evidences that these domains are not regions with a temperature above Tc, as for hot spots. In fact this phenomenon appears to be analog to the nucleation of phase-slip centers observed in conventional superconductors near Tc, but here in contrast they appear in a wide temperature range. Under some conditions, these domains will propagate and destroy the superconductivity within the whole sample. We have measured the temperature dependence of j* and found a similar behavior in the two investigated compounds. This temperature dependence is just the one expected for the depairing current, but the amplitude is about 100 times smaller.