Transport through a Majorana island: strong tunneling regime

TL;DR

This paper investigates how strong hybridization of Majorana modes affects transport in a topological superconducting nanowire within the Coulomb blockade regime, revealing modifications in conductance due to competing effects of hybridization and charging energy.

Contribution

It provides a detailed analysis of the impact of Majorana mode hybridization on Coulomb blockade phenomena in topological nanowires, a novel aspect in topological quantum transport studies.

Findings

Hybridization broadening modifies Coulomb blockade features.

Conductance depends on gate voltage and junction transmission.

Majorana modes enable non-local single-electron transmission.

Abstract

In the presence of Rashba spin-orbit coupling, magnetic field can drive a proximitized nanowire into a topological superconducting phase. We study transport properties of such nanowires in the Coulomb blockade regime. The associated with the topological superconductivity Majorana modes significantly modify transport and lead to single-electron coherent transmission through the nanowire - a non-local signature of topological superconductivity. In this work, we focus on the case of strong hybridization of the Majorana modes with the normal leads. The induced by hybridization broadening of the Majorana zero-energy states competes with the charging energy, leading to a considerable modification of the Coulomb blockade in a nanowire contacted by two normal leads. We evaluate the two-terminal conductance as a function of the gate voltage, junctions transmission coefficients, the geometric capacitance of and the induced superconducting gap in the nanowire.