Quantum control of electron transport

Recent experiments have demonstrated the coupling of superconducting quantum circuits to quantum electronic conductors. Such hybrid quantum systems allow the study of new physical regimes and also offer the possibility of applications in quantum information processing. We have studied the effect of a quantum microwave field on the electron transport statistics through a coupled quantum electronic conductor [Nature Communications5, 5562 (2014)].We determined the current and current noise of the conductor, generalizing the standard theories of photon-assisted tunnelling and dynamical Coulomb blockade. We showed that the emission and absorption of photons by the tunnelling electrons is naturally characterized by a quasi-probability distribution, closely related to the phase-space distribution functions of quantum optics. Our results suggest the potential of such a system for controlling electron transport using microwaves, and measuring microwaves using electron transport.