Josephson tunnel junction controlled by quasiparticle injection

Abstract

A Josephson tunnel junction transistor based on quasiparticle injection is proposed. Its operationrelies on the manipulation of the electron distribution in one of the junction electrodes. This isaccomplished by injecting quasiparticle current through the junction electrode by two additionaltunnel-coupled superconductors. Both large supercurrent enhancement and fast quenching can beachieved with respect to equilibrium by varying quasiparticle injection for proper temperatureregimes and suitable superconductor combinations. Combined with large power gain, this makes thedevice attractive for applications where reduced noise and low-power dissipation are required.