A proposal to probe quantum non-locality of Majorana fermions in tunneling experiments

TL;DR

This paper proposes a novel tunneling experiment to uniquely identify Majorana fermions in semiconductor quantum wires, addressing limitations of previous signatures like zero bias peaks and fractional Josephson effects.

Contribution

It introduces a specific tunneling setup capable of distinguishing Majorana fermions from trivial zero-energy states, advancing experimental detection methods.

Findings

Proposes a tunneling experiment to identify Majorana fermions.

Shows the experiment can differentiate MFs from trivial zero-energy states.

Addresses limitations of previous signatures like teleportation experiments.

Abstract

Topological Majorana fermion (MF) quasiparticles have been recently suggested to exist in semiconductor quantum wires with proximity induced superconductivity and a Zeeman field. Although the experimentally observed zero bias tunneling peak and a fractional ac-Josephson effect can be taken as necessary signatures of MFs, neither of them constitutes a sufficient "smoking gun" experiment. Since one pair of Majorana fermions share a single conventional fermionic degree of freedom, MFs are in a sense fractionalized excitations. Based on this fractionalization we propose a tunneling experiment that furnishes a nearly unique signature of end state MFs in semiconductor quantum wires. In particular, we show that a "teleportation"-like experiment is not enough to distinguish MFs from pairs of MFs, which are equivalent to conventional zero energy states, but our proposed tunneling experiment, in principle, can make this distinction.