We study time-dependent electron transport through an Anderson model. The
electronic interactions on the impurity site are included via the self-energy
approximations at Hartree-Fock (HF), second Born (2B), GW, and T-Matrix level
as well as within a time-dependent density functional (TDDFT) scheme based on
the adiabatic Bethe-Ansatz local density approximation (ABALDA) for the
exchange correlation potential. The Anderson model is driven out of equilibrium
by applying a bias to the leads and its nonequilibrium dynamics is determined
by real-time propagation. The time-dependent currents and densities are
compared to benchmark results obtained with the time-dependent density matrix
renormalization group (tDMRG) method. Many-body perturbation theory beyond HF
gives results in close agreement with tDMRG especially within the 2B
approximation. We find that the TDDFT approach with the ABALDA approximation
produces accurate results for the densities on the impurity site but
overestimates the currents. This problem is found to have its origin in an
overestimation of the lead densities which indicates that the exchange
correlation potential must attain nonzero values in the leads.Comment: 11 pages, 9 figure