Superconductivity-Related Insulating Behavior

TL;DR

This study investigates the transition from superconducting to insulating states in disordered amorphous Indium Oxide films under magnetic fields, revealing related conduction mechanisms and disorder effects.

Contribution

It provides experimental insights into the magnetic-field-induced superconductor-insulator transition and the relationship between superconducting and insulating conduction mechanisms.

Findings

Insulating state shows activated transport with a characteristic temperature $T_I$

Maximum $T_I$ is close to the zero-field $T_c$, indicating a connection between phases

Disorder affects $T_I^p$ and $T_c$ oppositely

Abstract

We present the results of an experimental study of superconducting, disordered, thin-films of amorphous Indium Oxide. These films can be driven from the superconducting phase to a reentrant insulating state by the application of a perpendicular magnetic field ($B$). We find that the high-$B$ insulator exhibits activated transport with a characteristic temperature, $T_I$. $T_I$ has a maximum value ($T_{I}^p$) that is close to the superconducting transition temperature ($T_c$) at $B$ = 0, suggesting a possible relation between the conduction mechanisms in the superconducting and insulating phases. $T_{I}^p$ and $T_c$ display opposite dependences on the disorder strength.