Time-dependent quantum transport through interacting systems using the Kadanoff-Baym equations
Prof. Dr. Robert van Leeuwen
(Department of Physics, Nanoscience Center, University of Jyväskylä, Finland)
14.04.2010
We propose a time-dependent many-body approach to study the short-time dynamics of correlated electrons in quantum transport through nanoscale systems contacted to metallic leads.This approach is based on the time propagation of the Kadanoff-Baym equations for the nonequilibrium many-body Green’s function of open and interacting systems out of equilibrium. An important feature of the method is that it takes full account of electronic correlations and embedding effects in the presence of time-dependent external fields, while at the same time satisfying the charge conservation law.
The method further extends the Meir-Wingreen formula to the time domain for initially correlated states. We study the electron dynamics of a correlated quantum wire attached to two-dimensional leads exposed to a sudden switch on of a bias voltage using conserving many-body approximations at Hartree-Fock, second Born and GW level. We obtain detailed results for the transient currents, dipole moments, and spectral functions of the quantum wire as well as for the time-dependent density pattern in the leads, and we show how the time dependence of these observables provides a wealth of information on the energy level structure of the quantum wire out of equilibrium.