Phase-sensitive SQUIDs based on the 3D topological insulator HgTe

TL;DR

This paper reports on the development and measurement of phase-sensitive SQUIDs made from the 3D topological insulator HgTe, aiming to explore unconventional superconductivity induced by topological surface states.

Contribution

It introduces SQUIDs based on strained HgTe, a 3D topological insulator, as a novel platform to study proximity-induced p-wave superconductivity.

Findings

Successful fabrication of HgTe-based SQUIDs

Evidence of phase-sensitive measurements on topological surface states

Potential to observe unconventional superconductivity effects

Abstract

Three-dimensional topological insulators represent a new class of materials in which transport is governed by Dirac surface states while the bulk remains insulating. Due to helical spin polarization of the surface states, the coupling of a 3D topological insulator to a nearby superconductor is expected to generate unconventional proximity induced $p$-wave superconductivity. We report here on the development and measurements of SQUIDs on the surface of strained HgTe, a 3D topological insulator, as a potential tool to investigate this effect.