Coherent transport through a Majorana island in an Aharonov\u2013Bohm interferometer

A M Whiticar,T Wang,S Gronin,A Fornieri,E C T O’Farrell,A C C Drachmann,C M Marcus,C Thomas,G C Gardner,R Kallaher,F Nichele,M J Manfra

doi:10.1038/s41467-020-16988-x

Abstract

Majorana zero modes are leading candidates for topological quantum computation due to non-local qubit encoding and non-abelian exchange statistics. Spatially separated Majorana modes are expected to allow phase-coherent single-electron transport through a topological superconducting island via a mechanism referred to as teleportation. Here we experimentally investigate such a system by patterning an elongated epitaxial InAs-Al island embedded in an Aharonov-Bohm interferometer. With increasing parallel magnetic field, a discrete sub-gap state in the island is lowered to zero energy yielding persistent 1e-periodic Coulomb blockade conductance peaks (e is the elementary charge). In this condition, conductance through the interferometer is observed to oscillate in a perpendicular magnetic field with a flux period of h/e (h is Planck’s constant), indicating coherent transport of single electrons through the islands, a signature of electron teleportation via Majorana modes.

Highlights

Majorana zero modes are leading candidates for topological quantum computation due to non-local qubit encoding and non-abelian exchange statistics
Initial experiments reporting signatures of Majorana zero modes (MZMs) in hybrid superconductor–semiconductor nanowires focussed on zero-bias conductance peaks (ZBPs) using local tunneling spectroscopy[1,2,3,4]
Majorana islands provided additional evidence of MZMs based on nearly 1e-spaced Coulomb blockade (CB) peaks[5], and indicated a Rashba-like spin–orbit coupling with the spin–orbit field lying inplane, perpendicular to the wire axis[6]

Summary

Introduction

Majorana zero modes are leading candidates for topological quantum computation due to non-local qubit encoding and non-abelian exchange statistics. If single-electron transport in both the reference arm and the Majorana island is coherent, conductance through the interferometer is expected to show oscillations with a flux period h/e11,16.

Results

Conclusion