In this work, we study the role of bound electrons in quantum transport. The partition-free approach by Cini [Phys. Rev. B. 22, 5887 (1980)] is combined with time-dependent density-functional theory (TDDFT) to calculate total currents and densities in interacting systems. We show that the biased electrode-device-electrode system with bound states does not evolve toward a steady regime. The density oscillates with history-dependent amplitudes and, as a consequence, the effective potential of TDDFT oscillates too. Such time dependence might open new conductive channels, an effect which is not accounted for in any steady-state approach and might deserve further investigations.

• Received 19 September 2006

DOI:https://doi.org/10.1103/PhysRevB.75.195115