Nonequilibrium transport in mesoscopic multi-terminal SNS Josephson junctions

Abstract

We report the results of several nonequilibrium experiments performed on superconducting/normal/superconducting (S/N/S) Josephson junctions containing either one or two extra terminals that connect to normal reservoirs. Currents injected into the junctions from the normal reservoirs induce changes in the electron energy distribution function, which can change the properties of the junction. A simple experiment performed on a 3-terminal sample demonstrates that quasiparticle current and supercurrent can coexist in the normal region of the S/N/S junction. When larger voltages are applied to the normal reservoir, the sign of the current-phase relation of the junction can be reversed, creating a "$\pi$-junction." We compare quantitatively the maximum critical currents obtained in 4-terminal $\pi$-junctions when the voltages on the normal reservoirs have the same or opposite sign with respect to the superconductors. We discuss the challenges involved in creating a "Zeeman" $\pi$-junction with a parallel applied magnetic field and show in detail how the orbital effect suppresses the critical current. Finally, when normal current and supercurrent are simultaneously present in the junction, the distribution function develops a spatially inhomogeneous component that can be interpreted as an effective temperature gradient across the junction, with a sign that is controllable by the supercurrent. Taken as a whole, these experiments illustrate the richness and complexity of S/N/S Josephson junctions in nonequilibrium situations.

16 pages, 17 figures

References in corpus (19)

• Coupling of two superconductors through a ferromagnet : evidence for a pi-junction
• Quasiclassical Green's function approach to mesoscopic superconductivity
• Local Density of States in a Dirty Normal Metal connected to a Superconductor
• Phase coherent transport in hybrid superconducting nanostructures
• Density of states in a superconductor carrying a supercurrent
• The 1/3-shot noise suppression in diffusive nanowires
• Supercurrent-carrying density of states in diffusive mesoscopic Josephson weak links
• Phase Dependent Thermopower in Andreev Interferometers
• Magnetic Interference Patterns and Vortices in Diffusive SNS junctions
• Energy Resolved Supercurrent between two superconductors
• Density of states and supercurrent in diffusive SNS junctions: role of nonideal interfaces and spin-flip scattering
• Non-equilibrium supercurrent through mesoscopic ferromagnetic weak links
• Observation of a controllable PI-junction in a 3-terminal Josephson device
• Josephson effects in a superconductor-normal metal mesoscopic structure with a dangling superconducting arm
• Thermopower in Andreev interferometers
• Magnetic Field Effect on the Supercurrent of an SNS junction
• Supercurrent-induced Peltier-like effect in superconductor/normal-metal weak links
• Supercurrent-induced temperature gradient across a nonequilibrium SNS Josephson junction
• Peltier effects in Andreev interferometers

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• φ-State and Inverted Fraunhofer Pattern in Nonaligned Josephson Junctions
• Hysteresis in superconducting short weak links and $\mu$-SQUIDs
• Ferromagnetic Materials for Josephson π Junctions
• Josephson current in nanofabricated V/Cu/V mesoscopic junctions
• Intrinsic spin-orbit interaction in diffusive normal wire Josephson weak links: supercurrent and density of states
• Spin-polarized triplet supercurrent in Josephson junctions with perpendicular ferromagnetic layers
• Triplet contribution to the Josephson current in the nonequilibrium superconductor/ferromagnet/superconductor junction
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• Nonequilibrium Andreev resonances in ballistic graphene Andreev interferometers
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