Off-resonant two-photon-assisted electron transfer between quantum dots

Electron transfer between bound states of remote quantum dots driven by an off-resonant electromagnetic pulse is analyzed. In the case of nearly equal energies of the states, a two-photon transfer mechanism related to the high-frequency off-resonant Stark effect is proposed. An equivalent transformation is used to derive an effective Hamiltonian that provides a basis for correct treatment of continuum (conduction-band) states. It is shown that optimal conditions for electron transfer correspond to quasi-resonant excitation of states near the lower edge of the continuum. The characteristics of the process are evaluated.