Fano effect in the Coulomb blockade regime for a parallel-coupled double quantum dot system

Within the Keldysh non-equilibrium Green function formalism, the electronic transport is theoretically studied through a parallel-coupled double quantum dot (DQD). In Coulomb blockage regime, four states in the DQD system, corresponding to the bonding and antibonding molecular states due to the inter-dot coupling and their Coulomb blockade counterparts, each could contribute to the Resonant transport as a Breit-Wigner scatter in the single-particle picture, which is secured in the Hartree-Fock approximation we applied. The Fano effect arises in conductance spectra as the result of interference between the four states. Moreover, the possibility of manipulating the Fano lineshape is also investigated by tuning dot-lead couplings and the magnetic flux threading the ring connecting the dots and leads, in particular a possible swap effect, which might be as a qubit applied to the quantum computation. (c) 2006 Elsevier B.V. All rights reserved.