Photon-assisted Stückelberg-like oscillations in a double quantum dot

The time-dependent charge transfer between quantum dots induced by an ultrashort electric field is theoretically analyzed. For a double quantum dot coupled to metallic reservoirs we show that the electron-tunneling processes are analogous to those occurring in collisions between ions and atoms. As a consequence, the total current exhibits Stückelberg-like oscillations as a function of the duration and amplitude of the external field. This effect leads to a remarkable enhancement of the nonlinear response.