Observation of a Majorana zero mode in a topologically protected edge channel

TL;DR

This study demonstrates the detection of a Majorana zero mode in a topologically protected edge channel using scanning tunneling microscopy, revealing its spin signature and potential for quantum computing applications.

Contribution

It provides experimental evidence of a Majorana zero mode in a topological insulator edge channel with magnetic clusters, combining microscopy and theoretical modeling.

Findings

Detection of a localized Majorana zero mode at the edge-magnet interface

Observation of the Majorana spin signature distinguishing it from trivial states

Confirmation of proximity-induced superconductivity in helical edge states

Abstract

Superconducting proximity pairing in helical edge modes, such as those of topological insulators (TI), is predicted to provide a unique platform for realizing Majorana zero modes (MZMs). We use scanning tunneling microscopy measurements to probe the influence of proximity induced superconductivity and magnetism on the helical hinge states of Bi(111) films, grown on a superconducting Nb substrate and decorated with magnetic Fe clusters. Consistent with model calculations, our measurements reveal the emergence of a localized MZM at the interface between the superconducting helical edge channel and the Fe clusters with strong magnetization component along the edge. Our experiments also resolve the MZM spin signature that distinguishes it from trivial in-gap states that may accidently occur at zero energy in a superconductor.