01/05/2012
Observation
of quantum interference in molecular charge transport
By: Omar Gómez Rojas ID:139236
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 but it has proved to be difficult to exert control
over the wavefunction at higher temperatures. Molecules have typical energy
level spacings (~eV) that are much larger than the thermal energy at 300 K (~25
meV), and are therefore natural candidates for such experiments. Previously,
phenomena such as giant magnetoresistance5, Kondo effects and conductance
switching have been observed in single molecules, and theorists have predicted
that it should also be possible to observe quantum interference in molecular
conductors, 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 π-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.
Find more information on this work in: http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2012.37.html
Nature Nanotechnology (2012)
Observation of quantum interference in molecular charge transport
Constant M. Guédon, Hennie
Valkenier, Troels Markussen, Kristian S. Thygesen, Jan C. Hummelen & Sense Jan van der Molen
Published online 25 March 2012
DOI: 10.1038/nnano.2012.37
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