@article{18031,
  abstract     = {Molecular-scale components are expected to be central to the realization of nanoscale electronic devices1,2,3. Although molecular-scale switching has been reported in atomic quantum point contacts4,5,6, single-molecule junctions provide the additional flexibility of tuning the on/off conductance states through molecular design. To date, switching in single-molecule junctions has been attributed to changes in the conformation or charge state of the molecule7,8,9,10,11,12. Here, we demonstrate reversible binary switching in a single-molecule junction by mechanical control of the metal–molecule contact geometry. We show that 4,4'-bipyridine–gold single-molecule junctions can be reversibly switched between two conductance states through repeated junction elongation and compression. Using first-principles calculations, we attribute the different measured conductance states to distinct contact geometries at the flexible but stable nitrogen–gold bond: conductance is low when the N–Au bond is perpendicular to the conducting π-system, and high otherwise. This switching mechanism, inherent to the pyridine–gold link, could form the basis of a new class of mechanically activated single-molecule switches.},
  author       = {Quek, Su Ying and Kamenetska, Maria and Steigerwald, Michael L. and Choi, Hyoung Joon and Louie, Steven G. and Hybertsen, Mark S. and Neaton, J. B. and Venkataraman, Latha},
  issn         = {1748-3395},
  journal      = {Nature Nanotechnology},
  number       = {4},
  pages        = {230--234},
  publisher    = {Springer Nature},
  title        = {{Mechanically controlled binary conductance switching of a single-molecule junction}},
  doi          = {10.1038/nnano.2009.10},
  volume       = {4},
  year         = {2009},
}