Effects of non-orthogonality and electron correlations on the time-dependent current through quantum dots

Three issues are analyzed in the physics of time-dependent tunneling current through a quantum dot with strongly correlated electrons coupled to two external contact leads: (i) nonorthogonality of the states of electrons in the leads and in the quantum dot, (ii) non-Fermi statistics of the excitations in the quantum dot, and iii) kinematic shift of the quantum dot levels. The contributions from nonorthogonality effectively decrease the mixing interaction between the leads and the quantum dot and the width of the quantum dot level whereas the Gibbs statistics slightly changes the spectral weights of quantum dot levels, and decreases the widths, but does not introduce drastical changes to the current. The kinematic interactions are taken into account within the loop correction. For the case of block signal, the time-dependent current shows oscillations starting at the onset and termination of the bias voltage pulse.