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 the superconducting order parameter on a local scale through the Ambegaokar-Baratoff (AB) relation. Using single atomic contacts created by means of atom manipulation, we demonstrate that in the extreme case of a single transport channel through the atomic junction modifications of the current-phase relation lead to significant deviations from the linear AB formula relating the critical current to the involved gap parameters. Using the full current-phase relation for arbitrary channel transmission, we model the Josephson effect in the dynamical Coulomb blockade regime because the charging energy of the junction capacitance cannot be neglected. We find excellent agreement with the experimental data. Projecting the current-phase relation onto the charge transfer operator shows that at high transmission multiple Cooper pair tunneling may occur. These deviations become non-negligible in Josephson-STM, for example, when scanning across single adatoms.

arXiv comment9 pages, 6 figures, including supplementary information

References in corpus (19)

• Hamiltonian approach to the transport properties of superconducting quantum point contacts
• Detection of a Cooper-Pair Density Wave in Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+x}$
• Spectral Properties of Quasiparticle Excitations Induced by Magnetic Moments in Superconductors
• Microscopic origin of the conducting channels in metallic atomic-size contacts
• Measurement of the current-phase relation of superconducting atomic contacts
• Local Electronic Structure of a Single Magnetic Impurity in a Superconductor
• Fluctuation Dominated Josephson Tunneling with a Scanning Tunneling Microscope
• Microscopic Theory of Josephson Mesoscopic Constrictions
• The energy resolution function of a tunnel junction
• On the use of STM superconducting tips at very low temperatures
• Full counting statistics of multiple Andreev reflections
• Scanning Josephson spectroscopy on the atomic scale
• Josephson scanning tunneling microscopy
• DC-transport in superconducting point contacts: a full counting statistics view
• Critical Josephson current in the dynamical Coulomb blockade regime
• Microwave photon-assisted phase-incoherent Cooper-pair tunneling in a Josephson STM
• Probing the superconducting condensate on a nanometer scale
• Imaging the Spatial Form of a Superconducting Order Parameter via Josephson Scanning Tunneling Spectroscopy
• Friedel oscillations and Majorana zero modes in inhomogeneous superconductors

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• Josephson spectroscopy study of kagome superconductors toward the deep point-contact regime
• Towards a $\cos (2\phi )$ Josephson element using aluminum junctions with well-transmitted channels
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