Phase-sensitive transport at a normal metal-superconductor interface close to a Josephson junction

Abstract

Phase- and voltage bias-sensitive quasiparticle transport at a double $NI{S}_{1}I{S}_2$ interface is considered. The barriers $I$ range from tunnel to transparent, and the intermediate region $S_1$ has a width comparable to the superconducting coherence length. A phase difference $\phi$ is applied to the Josephson junction $S_{1}I{S}_2$. The normal and Andreev reflections at the $NI{S}_1$ interface become $\phi$-sensitive, and transport is governed by interferences within the narrow $S_1$ region, both in the normal and anomalous channels. The subgap conductance is separately (energy $E$)- and (phase $\phi$)- symmetric. Above the superconducting gap, the conductance is in general not symmetric even if $(E,\phi )$ is changed in $(-E,-\phi )$, but the symmetry is restored by averaging Fermi oscillations. The Tomasch oscillations are amplified by the phase difference. The subgap conductance exhibits a resonant structure at the energy of the Andreev bound states (ABS) of the $S_{1}I{S}_2$ junction, providing a side-spectroscopy of such states. Depending on the relative transparencies of the junctions, the resonance can increase or reduce the conductance, and it can even vanish for $\phi =\pi$, featuring total reflection of quasiparticles at $N{S}_1$ by the ABS at $S_1{S}_2$.

8 pages, 10 figures, 1 table

References in corpus (6)

• Evidence for crossed Andreev reflection in superconductor-ferromagnet hybrid structures
• Exciting Andreev pairs in a superconducting atomic contact
• Non-Local Correlations in Normal Metal-Superconducting Systems
• Production of non-local quartets and phase-sensitive entanglement in a superconducting beam splitter
• Voltage-induced Shapiro steps in a superconducting multi-terminal structure
• Multiple Andreev reflections in hybrid multiterminal junctions

Cited by in corpus (4)

• Enhancement of crossed Andreev reflection in a superconducting ladder connected to normal metal leads
• Inversion in a four-terminal superconducting device on the quartet line: I. Two-dimensional metal and the quartet beam splitter
• Ultralong-distance quantum correlations in three-terminal Josephson junctions
• Quartets and the Current-Phase Structure of a Double Quantum Dot Superconducting Bijunction at Equilibrium