Quantum Interference in Acyclic Systems: Conductance of Cross-Conjugated Molecules
Author(s):
Gemma C. Solomon, David Q. Andrews, Randall H. Goldsmith, Thorsten Hansen, Michael R. Wasielewski, Richard P. Van Duyne, Mark A. Ratner
Journal:
Journal of the American Chemical Society
Year:
2008
Volume:
130
Pages
17301-17308
DOI:
10.1021/ja8044053
Abstract:
We calculate that significant quantum interference effects can be observed in elastic electron
transport through acyclic molecules. Interference features are evident in the transmission characteristics
calculated for cross-conjugated molecules; significantly, these effects dominate the experimentally
observable conduction range. The unusual transport characteristics of these molecules are highlighted
through comparison with linearly conjugated and nonconjugated systems. The cross-conjugated molecules
presented here show a large dynamic range in conductance. These findings represent a new motif for
electron transfer through molecules that exhibit both very high and very low tunneling conductance states
accessible at low bias without nuclear motion. In designing single molecule electronic components, a large
dynamic range allows a high on/off ratio, a parameter of fundamental importance for switches, transistors,
and sensors.