Probing Majorana fermions in the tunneling spectra of a resonant level

TL;DR

This paper introduces a numerical method to identify Majorana fermions in superconducting chains by analyzing the tunneling spectra of a resonant level, aiding the experimental detection of topological quantum states.

Contribution

A new iterative two-site Bogoliubov transformation method for studying finite-size superconducting chains with Majorana fermions.

Findings

Resonant level spectra can distinguish Majorana peaks from Kondo resonances.

Method successfully applied to topological phase scenarios.

Provides a practical tool for experimental detection of Majorana fermions.

Abstract

Unambiguous identification of Majorana physics presents an outstanding problem whose solution could render topological quantum computing feasible. We develop a numerical approach to treat finite-size superconducting chains supporting Majorana fermions, which is based on iterative application of a two-site Bogoliubov transformation. We demonstrate the applicability of the method by studying a resonant level attached to the superconductor subject to external perturbations. In the topological phase, we show that the spectrum of a single resonant level allows to distinguish peak coming from Majorana physics from the Kondo resonance.