Transport properties of Majorana bound states networks in the Coulomb blockade regime

TL;DR

This paper investigates how Majorana bound states in nanowire networks influence electron transport, considering effects like charging energy and overlaps, to aid in characterizing these states for quantum computing applications.

Contribution

It provides a detailed analysis of transport mechanisms in MBS networks, including sequential tunneling and cotunneling, under Coulomb blockade conditions, highlighting experimental signatures.

Findings

Transport dominated by single-electron tunneling and Cooper pair processes.

Four-terminal measurements can characterize MBS properties.

Finite overlaps and charging energy affect transport signatures.

Abstract

Topologically protected qubits based on nanostructures hosting Majorana bound states (MBSs) hold great promise for fault-tolerant quantum computing. We study the transport properties of nanowire networks hosting MBSs with a focus on the effects of the charging energy and the overlap between neighboring MBSs in short mesoscopic samples. In particular, we investigate structures hosting four MBSs such as T-junctions and Majorana boxes. Using a master equation in the Markovian approximation, we discuss the leading transport processes mediated by the MBSs. Single-electron tunneling and processes involving creation and annihilation of Cooper pairs dominate in the sequential tunneling limit. In the cotunneling regime the charge in the MBSs network is fixed and transport is governed by transitions via virtual intermediate states. Our results show that four-terminal measurements in the T-junction and Majorana box geometries can be useful tools for the characterization of the properties of MBSs with finite overlaps and charging energy.