Pairing instabilities in topological insulator quantum wells

TL;DR

This paper investigates how induced attractive interactions in topological insulator quantum wells lead to various pairing instabilities, potentially resulting in exotic vortex lattice states and fractional quantum liquids, with a focus on the helical triplet pairing.

Contribution

It provides a theoretical analysis of pairing channels and predicts the helical triplet pairing instability in topological insulator quantum wells under proximity effects.

Findings

Identification of helical triplet pairing instability

Analysis of phase diagram tunable by gate voltage

Potential realization of vortex lattice and fractional quantum liquids

Abstract

Topological insulator quantum wells with induced attractive interactions between electrons are candidate systems for the realization of novel vortex lattice states with time-reversal symmetry, and incompressible quantum vortex liquids with fractional excitations. We analyze the competition between different pairing channels stimulated by the superconducting proximity effect in these quantum wells, and calculate the helical triplet pairing instability that can produce the mentioned phases using perturbation theory. We discuss the phase diagram tunable by gate voltage.