Majorana Fermion Induced Resonant Andreev Reflection

TL;DR

This paper investigates the experimental signatures of Majorana fermion edge states at superconductor-topological insulator interfaces, focusing on resonant Andreev reflections and conductance quantization related to vortex configurations.

Contribution

It provides a theoretical analysis of how Majorana fermions induce resonant Andreev reflections and quantized conductance signatures depending on vortex parity.

Findings

Resonant Andreev reflection occurs at Majorana fermion sites.

Linear conductance is quantized at 2e^2/h for odd vortex numbers.

Distinct conductance behavior for even versus odd vortex configurations.

Abstract

We describe experimental signatures of Majorana fermion edge states, which form at the interface between a superconductor and the surface of a topological insulator. If a lead couples to the Majorana fermions through electron tunneling, the Majorana fermions induce \textit{resonant} Andreev reflections from the lead to the grounded superconductor. The linear tunneling conductance is $0 $ ($2 e^2/h$) if there is an even (odd) number of vortices in the superconductor. Similar resonance occurs for tunneling into the zero mode in the vortex core. We also study the current and noise of a two-lead device.