Gate-induced superconductivity in a monolayer topological insulator

TL;DR

This paper reports the induction of superconductivity in a monolayer topological insulator WTe_2 through electrostatic doping, enabling gate-controlled topological superconducting states with potential quantum computing applications.

Contribution

It demonstrates for the first time that intrinsic superconductivity can be induced in a monolayer 2D topological insulator via electrostatic gating.

Findings

Superconductivity observed below 1 K in monolayer WTe_2.

Superconductivity can be toggled with small gate voltages.

The system combines topological edge states with superconductivity.

Abstract

The layered semimetal WTe_2 has recently been found to be a two-dimensional topological insulator (2D TI) when thinned down to a single monolayer, with conducting helical edge channels. We report here that intrinsic superconductivity can be induced in this monolayer 2D TI by mild electrostatic doping, at temperatures below 1 K. The 2D TI-superconductor transition can be easily driven by applying a just a small gate voltage. This discovery offers new possibilities for gate-controlled devices combining superconductivity and topology, and could provide a basis for quantum information schemes based on topological protection.