Destruction of localized electron pairs above the magnetic-field-driven superconductor-insulator transition in amorphous InO films

TL;DR

This study investigates how high magnetic fields destroy localized electron pairs in amorphous InO films, revealing a transition from superconducting to metallic or insulating phases with complex magnetoresistance behavior.

Contribution

It provides new insights into the field-induced destruction of localized electron pairs and the resulting phase transitions in amorphous InO films at very low temperatures.

Findings

Magnetoresistance peaks at the transition point.

High magnetic fields can induce metallic phases.

Resistance approaches transition value at high fields.

Abstract

We have investigated the field-induced superconductivity-destroying quantum transition in amorphous indium oxide films at low temperatures down to 30 mK. It has been found that, on the high-field side of the transition, the magnetoresistance reaches a maximum and the phase can be insulating as well as metallic. With further increasing magnetic field the film resistance drops and approaches in the high-field limit the resistance value at transition point so that at high fields the metallic phase occurs for both cases. We give a qualitative account of this behavior in terms of field-induced destruction of localized electron pairs.