  Charge transport through a nanoscale junction coupled to two macroscopic
electrodes is investigated for the situation when bound states are present. We
provide numerical evidence that bound states give rise to persistent,
non-decaying current oscillations in the junction. We also show that the
amplitude of these oscillations can exhibit a strong dependence on the history
of the applied potential as well as on the initial equilibrium configuration.
Our simulations allow for a quantitative investigation of several transient
features. We also discuss the existence of different time-scales and address
their microscopic origin.
