Electronic transport in ballistic multiterminal Nb/InAs hybrid devices

We report on the electronic transport in ballistic multiterminal superconductor-semiconductor-superconductor (SNS) hybrid devices. The supercurrent of a SNS transistor with an electrode separation of 500 nm and a width of 6 mum can be suppressed by the creation of a non-equilibrium occupation of the current carrying Andreev bound states. This is achieved by current injection either across or aside the N region of the junction. In samples for Andreev-level spectroscopy a peak-like structure is observed in the differential conductance vs. voltage drop between injector electrode and superconductor. The magnetic field dependence of the peak positions reveal a 2 pi periodicity on the phase difference between the two superconductors. This suggests the structure to be due to resonant tunneling of injected electrons into Andreev bound states.