Josephson Effect and Charge Distribution in Thin Bi2Te3 Topological Insulators

Martin P Stehno,Hiroaki Myoren,Alexander Brinkman,Prosper Ngabonziza

doi:10.1002/adma.201908351

Abstract

Thin layers of topological insulator materials are quasi-2D systems featuring a complex interplay between quantum confinement and topological band structure. To understand the role of the spatial distribution of carriers in electrical transport, the Josephson effect, magnetotransport, and weak anti-localization are studied in bottom-gated thin Bi2 Te3 topological insulator films. The experimental carrier densities are compared to a model based on the solutions of the self-consistent Schrödinger-Poisson equations and they are in excellent agreement. The modeling allows for a quantitative interpretation of the weak antilocalization correction to the conduction and of the critical current of Josephson junctions with weak links made from such films without any ad hoc assumptions.

Highlights

Thin layers of topological insulator materials are quasi-2D systems featuring with a spin structure that is linked to the crystal direction (”spin-momentuma complex interplay between quantum confinement and topological band locking”)
The modeling allows for a quantitative matter systems could potentially be used interpretation of the weak antilocalization correction to the conduction and of the critical current of Josephson junctions with weak links made from such films without any ad hoc assumptions
The energetic ordering of orbitals that create valence imity-induced superconductivity in Josephson devices fabricated and conduction bands is reversed and surface states emerge on thin films of these materials have been reported;[10,11,12,13,14,15] little is that are protected by the topology of the band structure.[1] known about the spatial distribution of carriers in normal state

Summary

Introduction

Thin layers of topological insulator materials are quasi-2D systems featuring with a spin structure that is linked to the crystal direction (”spin-momentuma complex interplay between quantum confinement and topological band locking”). Backed by the theoretical model, we are able to interpret the magnitude of the observed weak antilocalization correction to the conductivity quantitatively and conclude that the critical current of the Josephson devices maps the change in shape of the (sub)band structure of the thin film when a gate voltage is applied.

Results

Conclusion