Kavli Affiliate: Yu V. Nazarov

| First 5 Authors: C. Padurariu, T. Jonckheere, J. Rech, R. MÃ©lin, D. Feinberg

| Summary:

We describe the proximity effect in a short disordered metallic junction

between three superconducting leads. Andreev bound states in the multi-terminal

junction may cross the Fermi level. We reveal that for a quasi-continuous

metallic density of states, crossings at the Fermi level manifest as closing of

the proximity-induced gap. We calculate the local density of states for a wide

range of transport parameters using quantum circuit theory. The gap closes

inside an area of the space spanned by the superconducting phase differences.

We derive an approximate analytic expression for the boundary of the area and

compare it to the full numerical solution. The size of the area increases with

the transparency of the junction and is sensitive to asymmetry. The finite

density of states at zero energy is unaffected by electron-hole decoherence

present in the junction, although decoherence is important at higher energies.

Our predictions can be tested using tunneling transport spectroscopy. To

encourage experiments, we calculate the current-voltage characteristic in a

typical measurement setup. We show how the structure of the local density of

states can be mapped out from the measurement.

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