Single channel Josephson effect in a high transmission atomic contact

verfasst von: Jacob Senkpiel, Simon Dambach, Markus Etzkorn, Robert Drost, Ciprian Padurariu, Björn Kubala, Wolfgang Belzig, Alfredo Levy Yeyati, Juan Carlos Cuevas, Joachim Ankerhold, Christian R. Ast, Klaus Kern
Abstract: The Josephson effect in scanning tunneling microscopy (STM) is an excellent tool to probe the properties of a superconductor on a local scale. We use atomic manipulation in a low temperature STM to create mesoscopic single channel contacts and study the Josephson effect at arbitrary transmissions. We observe significant deviations from the Ambegaokar-Baratoff formula relating the critical current to the order parameter starting from transmissions of τ > 0.1. Using the full current-phase relation, we model the Josephson effect in the dynamical Coulomb blockade regime, where the charging energy of the junction capacitance cannot be neglected, and find excellent agreement with the experimental data. Projecting the current-phase relation onto the charge transfer operator shows that at high transmission, non-linear behaviour arises and multiple Cooper pair tunneling may occur. Our model includes these deviations, which become non-negligible in Josephson-STM, for example, when scanning across single adatoms.
Externe Organisation(en): Max-Planck-Institut für Festkörperforschung
Universität Ulm
Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)
Universität Konstanz
Universidad Autónoma de Madrid (UAM)
Eidgenössische Technische Hochschule Lausanne (ETHL)
Typ: Artikel
Journal: Communications Physics
Band: 3
Publikationsdatum: 01.12.2020
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Allgemeine Physik und Astronomie
Elektronische Version(en): https://doi.org/10.1038/s42005-020-00397-z (Zugang: Offen)

BibTeX

@article{f027193e83b24dafa6d0fb77ea7c21fc,
title = "Single channel Josephson effect in a high transmission atomic contact",
abstract = "The Josephson effect in scanning tunneling microscopy (STM) is an excellent tool to probe the properties of a superconductor on a local scale. We use atomic manipulation in a low temperature STM to create mesoscopic single channel contacts and study the Josephson effect at arbitrary transmissions. We observe significant deviations from the Ambegaokar-Baratoff formula relating the critical current to the order parameter starting from transmissions of τ > 0.1. Using the full current-phase relation, we model the Josephson effect in the dynamical Coulomb blockade regime, where the charging energy of the junction capacitance cannot be neglected, and find excellent agreement with the experimental data. Projecting the current-phase relation onto the charge transfer operator shows that at high transmission, non-linear behaviour arises and multiple Cooper pair tunneling may occur. Our model includes these deviations, which become non-negligible in Josephson-STM, for example, when scanning across single adatoms.",
author = "Jacob Senkpiel and Simon Dambach and Markus Etzkorn and Robert Drost and Ciprian Padurariu and Bj{\"o}rn Kubala and Wolfgang Belzig and Yeyati, {Alfredo Levy} and Cuevas, {Juan Carlos} and Joachim Ankerhold and Ast, {Christian R.} and Klaus Kern",
note = "Funding information: We gratefully acknowledge fruitful discussions with Berthold J{\"a}ck and Elke Scheer. Funding from the European Research Council for the Consolidator Grant ABSOLUTE-SPIN (Grant No. 681164), from the Spanish MINECO (Grant No. FIS2014-55486-P, FIS2017-84057-P and FIS2017-84860-R), from the “Mar{\'i}a de Maeztu” Programme for Units of Excellence in R&D (MDM-2014-0377), from the Zeiss Foundation, from the DFG through AN336/11-1 and from the IQST is also gratefully acknowledged. J.C.C. and W.B. acknowledge support from the DFG through SFB 767.",
year = "2020",
month = dec,
day = "1",
doi = "10.1038/s42005-020-00397-z",
language = "English",
volume = "3",
journal = "Communications Physics",
publisher = "Springer Nature",
number = "1",
}