Electrostatic Tuning of the Properties of Disordered Indium Oxide Films near the Superconductor-Insulator Transition

TL;DR

This study investigates how electrostatic gating influences the electrical and superconducting properties of amorphous indium oxide films near the superconductor-insulator transition, revealing tunable magnetoresistance features.

Contribution

It demonstrates controlled carrier density modulation in InO films using ionic liquid gating and links magnetoresistance behavior to granularity models.

Findings

Carrier density increased by up to 7×10^14 carriers/cm^2.

Magnetoresistance peak position and magnitude are tunable.

Results support a granularity-based model for insulating regime behavior.

Abstract

The evolution with carrier concentration of the electrical properties of amorphous indium oxide (InO) thin films has been studied using electronic double layer transistor configurations. Carrier variations of up to 7 X 10^(14) carriers/cm^2 were achieved using an ionic liquid as a gate dielectric. The superconductor-insulator transition was traversed and the magnitude and position of the large magnetoresistance peak found in the insulating regime were modified. The systematic variation of the magnetoresistance peak with charge concentration was found to be qualitatively consistent with a simulation based on a model involving granularity.