Electrostatic Tuning of the Superconductor-Insulator Transition in Two Dimensions

TL;DR

This paper demonstrates that electrostatic tuning can induce a superconductor-insulator transition in ultra-thin amorphous bismuth films, revealing insights into the role of electron interactions and universality classes.

Contribution

It shows how electric field effect can control superconductivity in ultra-thin films and links the transition to the 3D XY model universality class.

Findings

Superconductivity induced by electric field in amorphous bismuth films.

Screening of electron-electron interactions correlates with superconductivity.

Transition belongs to the 3D XY universality class.

Abstract

Superconductivity has been induced in insulating ultra-thin films of amorphous bismuth using the electric field effect. The screening of electron-electron interaction was found to increase with electron concentration in a manner correlated with the tendency towards superconductivity. This does not preclude an increase in the density of states being important in the development of superconductivity. The superconductor-insulator transition appears to belong to the universality class of the three dimensional XY model.