  The quantum master equation applied to electronic transport through
nanoscopic devices provides information not only on the stationary state but
also on the dynamics. The dynamics is characterized by the eigenvalues of the
transition-rate matrix, or generator, of the master equation. We propose to use
the spectrum of these eigenvalues as a tool for the study of nanoscopic
transport. We illustrate this idea by analyzing a molecular quantum dot with an
electronic orbital coupled to a vibrational mode, which shows the Franck-Condon
blockade if the coupling is strong. Our approach provides complementary
information compared to the study of observables in the stationary state.
