Journal article · Preprint article
Graphical prediction of quantum interference-induced transmission nodes in functionalized organic molecules
Quantum interference (QI) in molecular transport junctions can lead to dramatic reductions of the electron transmission at certain energies. In a recent work [Markussen et al., Nano Lett., 2010, 10, 4260] we showed how the presence of such transmission nodes near the Fermi energy can be predicted solely from the structure of a conjugated molecule when the energies of the atomic pz orbitals do not vary too much.
Here we relax the assumption of equal on-site energies and generalize the graphical scheme to molecules containing different atomic species. We use this diagrammatic scheme together with tight-binding and density functional theory calculations to investigate QI in linear molecular chains and aromatic molecules with different side groups.
For the molecular chains we find a linear relation between the position of the transmission nodes and the side group π orbital energy. In contrast, the transmission functions of functionalized aromatic molecules generally display a rather complex nodal structure due to the interplay between molecular topology and the energy of the side group orbital.
Language: | English |
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Publisher: | The Royal Society of Chemistry |
Year: | 2011 |
Pages: | 14311-14317 |
ISSN: | 14639084 and 14639076 |
Types: | Journal article and Preprint article |
DOI: | 10.1039/c1cp20924h |
ORCIDs: | Thygesen, Kristian Sommer |