Absence of Aharonov-Bohm effect of chiral Majorana fermion edge states

TL;DR

This paper investigates the detection of charge-neutral Majorana fermions via interferometry, revealing that their zero-bias conductance is flux-independent, unlike in graphene where Aharonov-Bohm effects are observed.

Contribution

It proposes a novel interferometry setup to detect Majorana fermions and demonstrates the absence of Aharonov-Bohm effects for these states in a superconductor-topological insulator system.

Findings

Zero-bias conductance is flux-independent for Majorana states.

Graphene setup shows clear Aharonov-Bohm effects.

Majorana states exhibit charge neutrality and zero-energy characteristics.

Abstract

Majorana fermions in a superconductor hybrid system are charge neutral zero-energy states. For the detection of this unique feature, we propose an interferometry of a chiral Majorana edge channel, formed along the interface between a superconductor and a topological insulator under an external magnetic field. The superconductor is of a ring shape and has a Josephson junction that allows the Majorana state to enclose continuously tunable magnetic flux. Zero-bias differential electron conductance between the Majorana state and a normal lead is found to be independent of the flux at zero temperature, manifesting the Majorana feature of a charge neutral zero-energy state. In contrast, the same setup on graphene has no Majorana state and shows Aharonov-Bohm effects.