Bias voltage dependence of charge imbalance effect in lateral superconductor/insulator/normal junctions

We measured a charge imbalance effect in superconduting narrow wires by injecting and detecting quasi-particles with S/I/N tunnel junctions. We observed a manifest excess current in the voltage–current characteristics of a detector junction. We extracted the excess current at finite bias voltages from the total tunneling current. The measured excess current had a characteristic dependence on the injection voltage.