Signatures of the Majorana spin in electrical transport through a Majorana nanowire

authored by: Alexander Schuray, Manuel Rammler, Patrik Recher
Abstract: In this paper, we investigate the transport properties of spinful electrons tunnel coupled to a finite-length Majorana nanowire on one end which is further tunnel coupled to a quantum dot (QD) at the other end. Using a full counting statistics approach, we show that Andreev reflection can happen in two separate channels that can be associated with the two spin states of the tunneling electrons. In a low-energy model for the nanowire that is represented by two overlapping Majorana bound states (MBSs) localized at the ends of the wire, analytical formulas for conductance and noise reveal their crucial dependence on the spin-canting angle difference of the two MBSs in the absence of the QD if the spinful lead couples to both MBSs. We further investigate the influence of a finite temperature on the observation of the coupling to both MBSs. In the presence of the QD, the interference of different tunneling paths gives rise to Fano resonances and the symmetry of those provide decisive information about the coupling to both MBSs. We contrast the low-energy model with a tight-binding model of the Majorana nanowire and treat the Coulomb interaction on the QD with a self-consistent mean field approach. Using the scattering matrix approach, we thereby extend the transport results obtained in the low-energy model including also higher excited states in the nanowire.
External Organisation(s): Technische Universität Braunschweig
Type: Article
Journal: Physical Review B
Volume: 102
ISSN: 2469-9950
Publication date: 15.07.2020
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Condensed Matter Physics
Electronic version(s): https://doi.org/10.1103/PhysRevB.102.045303 (Access: Unknown)

BibTeX

@article{f95233444709415398ac4850dad01aee,
title = "Signatures of the Majorana spin in electrical transport through a Majorana nanowire",
abstract = "In this paper, we investigate the transport properties of spinful electrons tunnel coupled to a finite-length Majorana nanowire on one end which is further tunnel coupled to a quantum dot (QD) at the other end. Using a full counting statistics approach, we show that Andreev reflection can happen in two separate channels that can be associated with the two spin states of the tunneling electrons. In a low-energy model for the nanowire that is represented by two overlapping Majorana bound states (MBSs) localized at the ends of the wire, analytical formulas for conductance and noise reveal their crucial dependence on the spin-canting angle difference of the two MBSs in the absence of the QD if the spinful lead couples to both MBSs. We further investigate the influence of a finite temperature on the observation of the coupling to both MBSs. In the presence of the QD, the interference of different tunneling paths gives rise to Fano resonances and the symmetry of those provide decisive information about the coupling to both MBSs. We contrast the low-energy model with a tight-binding model of the Majorana nanowire and treat the Coulomb interaction on the QD with a self-consistent mean field approach. Using the scattering matrix approach, we thereby extend the transport results obtained in the low-energy model including also higher excited states in the nanowire.",
author = "Alexander Schuray and Manuel Rammler and Patrik Recher",
note = "Funding information: We gratefully acknowledge the support of the Lower Saxony PhD-programme “Contacts in Nanosystems”, the Braunschweig International Graduate School of Metrology B-IGSM and the DFG Research Training Group 1952 Metrology for Complex Nanosystems.",
year = "2020",
month = jul,
day = "15",
doi = "10.1103/PhysRevB.102.045303",
language = "English",
volume = "102",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Institute of Physics",
number = "4",
}