Evidence of Majorana fermions in an Al - InAs nanowire topological superconductor

TL;DR

This paper reports experimental evidence and numerical simulations suggesting the existence of Majorana fermions in a hybrid superconductor-nanowire system, characterized by a zero bias conductance peak that is robust over various conditions.

Contribution

It provides new experimental data and simulations indicating the presence of Majorana-like states in an Al-InAs nanowire superconductor system, advancing the understanding of topological quantum states.

Findings

Observation of a zero bias conductance peak tied to the Fermi energy.

The ZBP appears only with a small magnetic field applied along the wire.

Data and simulations support the existence of Majorana fermions.

Abstract

Majorana fermions are the only fermionic particles that are expected to be their own antiparticles. While elementary particles of the Majorana type were not identified yet, quasi-particles with Majorana like properties, born from interacting electrons in the solid, were predicted to exist. Here, we present thorough experimental studies, backed by numerical simulations, of a system composed of an aluminum superconductor in proximity to an indium arsenide nanowire, with the latter possessing strong spin-orbit coupling. An induced 1d topological superconductor - supporting Majorana fermions at both ends - is expected to form. We concentrate on the characteristics of a distinct zero bias conductance peak (ZBP), and its splitting in energy, both appearing only with a small magnetic field applied along the wire. The ZBP was found to be robustly tied to the Fermi energy over a wide range of system parameters. While not providing a definite proof of a Majorana state, the presented data and the simulations support strongly its existence.