Magnetic-field influenced non-equilibrium transport through a quantum   ring with correlated electrons in a photon cavity
  We investigate magnetic-field influenced time-dependent transport of Coulomb interacting electrons through a two-dimensional quantum ring in an electromagnetic cavity under non-equilibrium conditions described by a time-convolutionless non-Markovian master equation formalism. We take into account the full electromagnetic interaction of electrons and cavity photons without resorting to the rotating wave approximation or reduction to two levels. A bias voltage is applied to semi-infinite leads along the x-axis, which are connected to the quantum ring. The magnetic field is tunable to manipulate the time-dependent electron transport coupled to a photon field with either x- or y-polarization. We find that the lead-system-lead current is strongly suppressed by the y-polarized photon field at magnetic field with two flux quanta due to a degeneracy of the many-body energy spectrum of the mostly occupied states. Furthermore, the current can be significantly enhanced by the y-polarized field at magnetic field with half integer flux quanta. 
Thorsten Arnold, Chi-Shung Tang, Andrei Manolescu and Vidar   Gudmundsson
cond-mat.mes-hall