Coherent photon assisted cotunneling in a Coulomb blockade device
  We study cotunneling in a double junction Coulomb blockade device under the influence of time dependent potentials. It is shown that the ac-bias leads to photon assisted cotunneling which in some cases may dominate the transport. We derive a general non-perturbative expression for the tunneling current in the presence of oscillating potentials and give a perturbative expression for the photon assisted cotunneling current. 
Karsten Flensberg (Danish Institute of Fundamental Metrology)