Probing Majorana bound states via counting statistics of a single electron transistor.

Zeng-Zhao Li,Chi-Hang Lam,J Q You

doi:10.1038/srep11416

Abstract

We propose an approach for probing Majorana bound states (MBSs) in a nanowire via counting statistics of a nearby charge detector in the form of a single-electron transistor (SET). We consider the impacts on the counting statistics by both the local coupling between the detector and an adjacent MBS at one end of a nanowire and the nonlocal coupling to the MBS at the other end. We show that the Fano factor and the skewness of the SET current are minimized for a symmetric SET configuration in the absence of the MBSs or when coupled to a fermionic state. However, the minimum points of operation are shifted appreciably in the presence of the MBSs to asymmetric SET configurations with a higher tunnel rate at the drain than at the source. This feature persists even when varying the nonlocal coupling and the pairing energy between the two MBSs. We expect that these MBS-induced shifts can be measured experimentally with available technologies and can serve as important signatures of the MBSs.

Highlights

We propose an approach for probing Majorana bound states (MBSs) in a nanowire via counting statistics of a nearby charge detector in the form of a single-electron transistor (SET)
It has been shown that a spin-orbit coupled semiconducting 2D thin film[14] or a 1D nanowire[15,16,17,18,19] with Zeeman spin splitting, which is in proximity to an s-wave superconductor, can host MBSs
With a conventional s-wave superconductor and a modest magnetic field, the MBSs as electron-hole quasiparticle excitations have been suggested to exist at the two ends of a semiconductor nanowire with strong spin-orbit coupling[14,18,19]

Summary

Introduction

We propose an approach for probing Majorana bound states (MBSs) in a nanowire via counting statistics of a nearby charge detector in the form of a single-electron transistor (SET). The minimum points of operation are shifted appreciably in the presence of the MBSs to asymmetric SET configurations with a higher tunnel rate at the drain than at the source This feature persists even when varying the nonlocal coupling and the pairing energy between the two MBSs. This feature persists even when varying the nonlocal coupling and the pairing energy between the two MBSs We expect that these MBS-induced shifts can be measured experimentally with available technologies and can serve as important signatures of the MBSs. Majorana fermions are particles that are their own antiparticles. In the presence of the MBSs, the minimum points shift appreciably to occur for an asymmetric SET with a higher tunnel rate at the drain than at the source

Methods

Results

Conclusion