Distinguishing a Majorana zero mode using spin resolved measurements

TL;DR

This paper demonstrates that spin-resolved measurements can uniquely identify Majorana zero modes in topological superconductors by revealing their nonlocal spin polarization, aiding in quantum computing research.

Contribution

It introduces spin polarization measurements as a novel diagnostic tool to distinguish topological MZMs from trivial in-gap states in superconductors.

Findings

MZMs exhibit spin polarization exceeding that of the host chains.

Spin polarization is linked to the nonlocality of MZMs in topological band structures.

Model calculations support the experimental observations.

Abstract

One-dimensional topological superconductors host Majorana zero modes (MZMs), the non-local property of which could be exploited for quantum computing applications. Spin- polarized scanning tunneling microscopy measurements show that MZMs realized in self- assembled Fe chains on the surface of Pb have a spin polarization that exceeds that due to the magnetism of these chains. This feature, captured by our model calculations, is a direct consequence of the nonlocality of the Hilbert space of MZMs emerging from a topological band structure. Our study establishes spin polarization measurements as a diagnostic tool to uniquely distinguish topological MZMs from trivial in-gap states of a superconductor.