Observation of quantum interference in molecular charge transport

Constant M. Guedon, Hennie Valkenier, Troels Markussen, Kristian S. Thygesen, Jan C. Hummelen, Sense Jan van der Molen

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

As the dimensions of a conductor approach the nanoscale, quantum effects begin to dominate, and it becomes possible to control the conductance through direct manipulation of the electron wavefunction. Such control has been demonstrated in various mesoscopic devices at cryogenic temperatures(1-4), but it has proved to be difficult to exert control over the wavefunction at higher temperatures. Molecules have typical energy level spacings (similar to eV) that are much larger than the thermal energy at 300 K (similar to 25 meV), and are therefore natural candidates for such experiments. Previously, phenomena such as giant magnetoresistance(5), Kondo effects(6) and conductance switching(7-11) have been observed in single molecules, and theorists have predicted that it should also be possible to observe quantum interference in molecular conductors(12-18), but until now all the evidence for such behaviour has been indirect. Here, we report the observation of destructive quantum interference in charge transport through two-terminal molecular junctions at room temperature. We studied five different rigid p-conjugated molecular wires, all of which form self-assembled monolayers on a gold surface, and find that the degree of interference can be controlled by simple chemical modifications of the molecular wire.
Original languageEnglish
JournalNature Nanotechnology
Volume7
Issue number5
Pages (from-to)304-308
ISSN1748-3387
DOIs
Publication statusPublished - 2012

Keywords

  • Nanoscience
  • Materials
  • Single molecule
  • Electron-transfer
  • Conductance
  • Junctions
  • Contacts

Cite this

Guedon, C. M., Valkenier, H., Markussen, T., Thygesen, K. S., Hummelen, J. C., & van der Molen, S. J. (2012). Observation of quantum interference in molecular charge transport. Nature Nanotechnology, 7(5), 304-308. https://doi.org/10.1038/NNANO.2012.37