2018/07/23 by É. G. Petrov, Ye. V. Shevchenko, Petrov, Elmar G. +9
Chemistry · Engineering · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Molecular Junctions and Nanostructures #Quantum and electron transport phenomena
paper · pdf · doi:10.48550/arxiv.1807.08558
openalex publication_date 2018/07/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The modified superexchange model is used to derive the expression for nonresonant tunneling conductance mediated by localized and delocalized molecular orbitals associated with the terminal and the interior molecular units respectively. The model is shown to work as long as delocalization of electron density in the chain's molecular orbitals is sustained during the tunneling. The criteria for reduction of the superexchange model of charge tunneling to the flat barrier model are formulated and the parameters of the barrier model (energy gap and effective electron mass) are specified in the terms of inter-site coupling and energy distance from the Fermi level to the delocalized wire's HOMO level. Application of the theory tothe experiment shows that the modified superexchange model is quite appropriate to explain the experimental results in case of the nonresonance tunneling conductance in --(CH2)N--NH2 and HOOC--(CH2)N--COOH molecular wires.