Inelastic effects in molecular junctions in the Coulomb and Kondo regimes: Nonequilibrium equation-of-motion approach

Inelastic effects in the Coulomb blockade and Kondo regimes of electron transport through molecular junctions are considered within a simple nonequilibrium equation-of-motion EOM approach. The scheme is self-consistent and can qualitatively reproduce the main experimental observations of vibrational features in the Coulomb blockade H. Park et al., Nature London 407, 57 2000 and Kondo L. H. Yu et al., Phys. Rev. Lett. 93, 266802 2004 regimes. Considerations similar to the equilibrium EOM approach by Meir et al. Phys. Rev. Lett. 66, 3048 1991 ; 70, 2601 1993 are used on the Keldysh contour to account for the nonequilibrium nature of the junction, and dressing by appropriate Franck-Condon factors is used to account for vibrational features. Results of the equilibrium EOM scheme by Meir et al. are reproduced in the appropriate limit.