Atomic-Scale Interface Engineering of Majorana Edge Modes in a 2D Magnet-Superconductor Hybrid System

TL;DR

This study demonstrates that atomic-scale interface engineering in a magnet-superconductor hybrid system enables the realization of topologically non-trivial states hosting Majorana edge modes, confirmed by both experimental visualization and theoretical calculations.

Contribution

It shows that an atomically thin oxide layer at the interface is essential for inducing topological superconductivity in a 2D hybrid system.

Findings

Visualization of chiral Majorana edge states via scanning tunneling spectroscopy

Interface engineering with an oxide layer induces topological phase transition

Theoretical calculations confirm the topologically non-trivial state with a non-zero Chern number

Abstract

Topological superconductors are predicted to harbor exotic boundary states - Majorana zero-energy modes - whose non-Abelian braiding statistics present a new paradigm for the realization of topological quantum computing. Using low-temperature scanning tunneling spectroscopy (STS), we here report on the direct real-space visualization of chiral Majorana edge states in a monolayer topological superconductor, a prototypical magnet-superconductor hybrid system comprised of nano-scale Fe islands of monoatomic height on a Re(0001)-O(2$\times$1) surface. In particular, we demonstrate that interface engineering by an atomically thin oxide layer is crucial for driving the hybrid system into a topologically non-trivial state as confirmed by theoretical calculations of the topological invariant, the Chern number.