title: Electron transport through a quantum dot assisted by cavity photons.
abstract: We investigate transient transport of electrons through a single quantum dot controlled by a plunger gate. The dot is embedded in a finite wire with length Lx assumed to lie along the x-direction with a parabolic confinement in the y-direction. The quantum wire, originally with hard-wall confinement at its ends, ±Lx/2, is weakly coupled at t = 0 to left and right leads acting as external electron reservoirs. The central system, the dot and the finite wire, is strongly coupled to a single cavity photon mode. A non-Markovian density-matrix formalism is employed to take into account the full electron-photon interaction in the transient regime. In the absence of a photon cavity, a resonant current peak can be found by tuning the plunger-gate voltage to lift a many-body state of the system into the source-drain bias window. In the presence of an x-polarized photon field, additional side peaks can be found due to photon-assisted transport. By appropriately tuning the plunger-gate voltage, the electrons in the left lead are allowed to undergo coherent inelastic scattering to a two-photon state above the bias window if initially one photon was present in the cavity. However, this photon-assisted feature is suppressed in the case of a y-polarized photon field due to the anisotropy of our system caused by its geometry.
authors.affiliation: Science Institute, University of Iceland, Dunhaga 3, IS-107 Reykjavik, Iceland.
authors.forename: Nzar Rauf
authors.initials: NR
authors.lastname: Abdullah
authors.forename: Chi-Shung
authors.initials: CS
authors.lastname: Tang
authors.forename: Andrei
authors.initials: A
authors.lastname: Manolescu
authors.forename: Vidar
authors.initials: V
authors.lastname: Gudmundsson