Majorana single-charge transistor

TL;DR

This paper analyzes electron transport in a Coulomb blockaded topological superconductor with Majorana states, deriving an exact current formula and revealing Coulomb oscillations, conductance behavior, and voltage sidebands.

Contribution

It provides the first exact formula for current in a Majorana single-charge transistor and explores its transport properties using multiple approaches.

Findings

Universal halving of peak conductance at finite temperature.

Coulomb oscillations with strong blockade.

Finite-voltage sidebands from anomalous tunneling.

Abstract

We study transport through a Coulomb blockaded topologically nontrivial superconducting wire (with Majorana end states) contacted by metallic leads. An exact formula for the current through this interacting Majorana single-charge transistor is derived in terms of wire spectral functions. A comprehensive picture follows from three different approaches. We find Coulomb oscillations with universal halving of the finite-temperature peak conductance under strong blockade conditions, where the valley conductance mainly comes from elastic cotunneling. The nonlinear conductance exhibits finite-voltage sidebands due to anomalous tunneling involving Cooper pair splitting.