Imaging doubled shot noise in a Josephson scanning tunneling microscope

Abstract

We have imaged the current noise with atomic resolution in a Josephson scanning tunneling microscope with a Pb-Pb junction. By measuring the current noise as a function of applied bias, we reveal the change from single electron tunneling above the superconducting gap energy to double electron charge transfer below the gap energy when Andreev processes become dominant. Our spatially resolved noise maps show that this doubling occurs homogeneously on the surface, also on impurity locations, demonstrating that indeed the charge pairing is not influenced by disruptions in the superconductor smaller than the superconducting coherence length.

arXiv comment5 pages, 5 figures

References in corpus (19)

• Shot Noise in Mesoscopic Conductors
• Random-Matrix Theory of Quantum Transport
• Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
• Quantum properties of atomic-sized conductors
• Observation of the e/3 Fractionally Charged Laughlin Quasiparticles
• Quantum suppression of shot noise in atom-size metallic contacts
• Observation of Andreev Reflection Enhanced Shot Noise
• Doubled Shot Noise In Disordered Normal-Metal-Superconductor Junctions
• Shot noise and coherent multiple charge transfer in superconducting quantum point-contacts
• Differential Conductance and Quantum Interference in Kondo Systems
• Experimental demonstration of a two-band superconducting state for lead using scanning tunneling spectroscopy
• Multiple Andreev Reflection and Giant Excess Noise in Diffusive Superconductor/Normal-Metal/Superconductor Junctions
• Doubled Full Shot Noise in Quantum Coherent Superconductor - Semiconductor Junctions
• Hysteresis and Noise from Electronic Nematicity in High Temperature Superconductors
• Scanning Josephson spectroscopy on the atomic scale
• Charge of a quasiparticle in a superconductor
• Amplifier for scanning tunneling microscopy at MHz frequencies
• Noisy defects in a doped Mott insulator
• Charge trapping and super-Poissonian noise centers in a cuprate high-temperature superconductor

Cited by in corpus (15)

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• Charge-$4e$ superconductivity from multi-component nematic pairing: Application to twisted bilayer graphene
• Direct evidence for Cooper pairing without a spectral gap in a disordered superconductor above $T_C$
• Photon-assisted tunneling at the atomic scale: Probing resonant Andreev reflections from Yu-Shiba-Rusinov states
• Spatially dispersing Yu-Shiba-Rusinov states in the unconventional superconductor ${\mathrm{FeTe}}_{0.55}{\mathrm{Se}}_{0.45}$
• Dynamical Coulomb Blockade as a Local Probe for Quantum Transport
• Coherent and incoherent tunneling into YSR states revealed by atomic scale shot-noise spectroscopy
• Spatial and energy resolution of electronic states by shot noise
• Cryogen-free scanning gate microscope for the characterization of Si/Si${}_{0.7}$Ge${}_{0.3}$ quantum devices at milli-Kelvin temperatures
• Single-electron charge transfer into putative Majorana and trivial modes in individual vortices
• Statistical detection of Josephson, Andreev, and single quasiparticle currents in scanning tunneling microscopy
• Shot-noise measurements of single-atom junctions
• Why shot noise does not generally detect pairing in mesoscopic superconducting tunnel junctions
• Local condensation of charge-$4e$ superconductivity at a nematic domain wall
• Non-Topological Edge-Localized Yu-Shiba-Rusinov States in CrBr${}_3$/NbSe${}_2$ Heterostructures