Conductance of a proximitized nanowire in the Coulomb blockade regime

TL;DR

This paper develops a quantitative theory for electron transport in proximitized nanowires under Coulomb blockade, highlighting how magnetic field tuning affects conductance peaks and signatures of topological transition.

Contribution

It introduces a comprehensive model describing conductance behavior in finite-length nanowires during topological transition, incorporating effects of spin-orbit interaction and Coulomb blockade.

Findings

Conductance peaks are shaped by Andreev reflection, single-electron, and resonant tunneling.

Magnetic field tuning reveals signatures of topological transition in conductance.

The theory aligns with experimental observations in proximitized nanowires.

Abstract

We identify the leading processes of electron transport across finite-length segments of proximitized nanowires and build a quantitative theory of their two-terminal conductance. In the presence of spin-orbit interaction, a nanowire can be tuned across the topological transition point by an applied magnetic field. Due to a finite segment length, electron transport is controlled by the Coulomb blockade. Upon increasing of the field, the shape and magnitude of the Coulomb blockade peaks in the linear conductance is defined, respectively, by Andreev reflection, single-electron tunneling, and resonant tunneling through the Majorana modes emerging after the topological transition. Our theory provides the framework for the analysis of experiments with proximitized nanowires, such as reported in Albrecht et al., Nature 531, 206-209 (2016), and identifies the signatures of the topological transition in the two-terminal conductance.