TY - JOUR
T1 - Resonant inelastic tunneling in molecular junctions
AU - Galperin, Michael
AU - Nitzan, Abraham
AU - Ratner, Mark A.
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2006
Y1 - 2006
N2 - Within a phonon-assisted resonance level model we develop a self-consistent procedure for calculating electron transport currents in molecular junctions with intermediate to strong electron-phonon interaction. The scheme takes into account the mutual influence of the electron and phonon subsystems. It is based on the second order cumulant expansion, used to express the correlation function of the phonon shift generator in terms of the phonon momentum Green function. Equation of motion (EOM) method is used to obtain an approximate analog of the Dyson equation for the electron and phonon Green functions in the case of many-particle operators present in the Hamiltonian. To zero order it is similar in particular cases (empty or filled bridge level) to approaches proposed earlier. The importance of self-consistency in resonance tunneling situations (partially filled bridge level) is stressed. We confirm, even for strong vibronic coupling, a previous suggestion concerning the absence of phonon sidebands in the current versus gate voltage plot when the source-drain voltage is small [Mitra, Phys. Rev. B 69, 245302 (2004)].
AB - Within a phonon-assisted resonance level model we develop a self-consistent procedure for calculating electron transport currents in molecular junctions with intermediate to strong electron-phonon interaction. The scheme takes into account the mutual influence of the electron and phonon subsystems. It is based on the second order cumulant expansion, used to express the correlation function of the phonon shift generator in terms of the phonon momentum Green function. Equation of motion (EOM) method is used to obtain an approximate analog of the Dyson equation for the electron and phonon Green functions in the case of many-particle operators present in the Hamiltonian. To zero order it is similar in particular cases (empty or filled bridge level) to approaches proposed earlier. The importance of self-consistency in resonance tunneling situations (partially filled bridge level) is stressed. We confirm, even for strong vibronic coupling, a previous suggestion concerning the absence of phonon sidebands in the current versus gate voltage plot when the source-drain voltage is small [Mitra, Phys. Rev. B 69, 245302 (2004)].
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U2 - 10.1103/PhysRevB.73.045314
DO - 10.1103/PhysRevB.73.045314
M3 - Article
AN - SCOPUS:33144480873
VL - 73
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 4
M1 - 045314
ER -