Interferometric and noise signatures of Majorana fermion edge states in transport experiments

TL;DR

This paper proposes experimental signatures of Majorana fermions in topological insulator-based transport setups, highlighting unique noise and interference patterns that distinguish Majorana states from conventional particles.

Contribution

It introduces a novel interferometric approach to detect Majorana fermions through noise correlations and predicts distinctive signatures such as zero average current, large shot noise, and absence of partition noise.

Findings

Average charge current in outgoing leads vanishes.

Large shot noise observed despite zero average current.

Absence of partition noise due to Majorana nature.

Abstract

Domain walls between superconducting and magnetic regions placed on top of a topological insulator support transport channels for Majorana fermions. We propose to study noise correlations in a Hanbury Brown-Twiss type interferometer and find three signatures of the Majorana nature of the channels. First, the average charge current in the outgoing leads vanishes. Furthermore, we predict an anomalously large shot noise in the output ports for a vanishing average current signal. Adding a quantum point contact to the setup, we find a surprising absence of partition noise which can be traced back to the Majorana nature of the carriers.