Quantum dot detects Majorana modes of both chiralities

TL;DR

This paper theoretically demonstrates that a quantum dot in a tunneling junction with a topological superconducting wire can reveal Majorana modes of both chiralities through distinctive spectral features, aiding their identification.

Contribution

It introduces a method where a quantum dot strongly coupled to a topological wire can detect Majorana modes of both chiralities via spectral density analysis.

Findings

Quantum dot reveals Majorana modes of both chiralities.

Three-peak spectral structures distinguish Majorana modes from trivial states.

Dot coupling enhances Majorana detection capabilities.

Abstract

A tunneling junction between normal electrode and a topological superconducting wire, mediated by a quantum dot, is considered theoretically. We show that the presence of the dot in the junction can be advantageous to Majorana zero modes identification. Namely, we demonstrate that for the dot strongly coupled to the wire, the Majorana mode from the upper chiral sub-band "leaks" into the dot, providing supplementary information on Majorana mode formation. Thus, both the Zeeman-split dot sub-levels detect Majorana partners of a Kramers pair, formed at the wire end. The characteristic three-peak structures in both spin sectors of the spectral density of the dot, distinguish from the trivial scenario of one Andreev resonance at Fermi energy produced exclusively by the dot's spin sub-levels.