Microwave quantum optics and electron transport through a metallic
dot strongly coupled to a transmission line cavity
Christian Bergenfeldt
Tuesday, 22 November 2011, 12:30
Matfys library
Abstract:
We investigate theoretically the properties of the photon state and the
electronic transport in a system consisting of a metallic dot strongly
coupled to a superconducting microwave
transmission line cavity. Within the framework of circuit quantum
electrodynamics we derive a Hamiltonian for arbitrary strong capacitive
coupling between the dot and the cavity. The dynamics of the system is
described by a quantum master equation, accounting for the electronic
transport as well as the coherent, non-equilibrium properties of the
photon state. The photon state is investigated, focusing on, for a single
active mode, signatures of microwave polaron formation and the effects of
a non-equilibrium photon distribution. For two active photon modes, intra
mode conversion and polaron coherences are investigated. For the
electronic transport, electrical current and noise through the dot and
the influence of the photon state on the transport properties are at the
focus. We identify clear transport signatures due to the non-equilibrium
photon population, in particular the emergence of superpoissonian
shot-noise at ultrastrong dot-cavity couplings.