Electric breakdown effect in the current-voltage characteristics of amorphous indium oxide thin films near the superconductor-insulator transition

TL;DR

This study investigates the electric breakdown in amorphous indium oxide thin films near the superconductor-insulator transition, revealing inhomogeneity and percolative conduction pathways through detailed current-voltage measurements.

Contribution

It uncovers the granular nature of breakdown and the presence of multiple small jumps, indicating inhomogeneity and percolation effects near the transition.

Findings

Multiple small jumps in I-V curves suggest inhomogeneity.

Breakdown proceeds via percolative paths across the film.

Inhomogeneity develops near the superconductor-insulator transition.

Abstract

Current-voltage characteristics in the insulator bordering superconductivity in disordered thin films exhibit current jumps of several orders of magnitude due to the development of a thermally bistable electronic state at very low temperatures. In this high-resolution study we find that the jumps can be composed of many (up to 100) smaller jumps that appear to be random. This indicates that inhomogeneity develops near the transition to the insulator and that the current breakdown proceed via percolative paths spanning from one electrode to the other.