title: Molecular diodes enabled by quantum interference.
abstract: We use scanning tunneling microscope break-junction (STM-BJ) measurements to study the low-bias conductance and high-bias current-voltage (IV) characteristics of a series of asymmetric para-meta connected diphenyl-oligoenes. From tight-binding calculations, we determine that the quantum interference features inherent in our molecular design result in a 'through-bond' coupling on the para-side, and through-space coupling on the meta-side. We show that these molecular junctions form single molecule diodes, and show that the rectification results from a difference in the voltage dependence of the coupling strength on the through-bond and the through-space side. The interplay between the applied voltage and the molecule-metal coupling results from the asymmetric polarizability of the conducting orbital under an external field.
authors.affiliation: Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA. lv2117@columbia.edu.
authors.forename: Arunabh
authors.initials: A
authors.lastname: Batra
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Meisner
authors.forename: Pierre
authors.initials: P
authors.lastname: Darancet
authors.forename: Qishui
authors.initials: Q
authors.lastname: Chen
authors.forename: Michael L
authors.initials: ML
authors.lastname: Steigerwald
authors.forename: Colin
authors.initials: C
authors.lastname: Nuckolls
authors.forename: Latha
authors.initials: L
authors.lastname: Venkataraman