title: Gap distance and interactions in a molecular tunnel junction.
abstract: The distance between electrodes in a tunnel junction cannot be determined from the external movement applied to the electrodes because of interfacial forces that distort the electrode geometry at the nanoscale. These distortions become particularly complex when molecules are present in the junction, as demonstrated here by measurements of the AC response of a molecular junction over a range of conductivities from microsiemens to picosiemens. Specific chemical interactions within the junction lead to distinct features in break-junction data, and these have been used to determine the electrode separation in a junction functionalized with 4(5)-(2-mercaptoethyl)-1H-imidazole-2-carboxamide, a reagent developed for reading DNA sequences.
authors.affiliation: Department of Physics, Arizona State University, Tempe, Arizona 85287, USA.
authors.forename: Shuai
authors.initials: S
authors.lastname: Chang
authors.forename: Jin
authors.initials: J
authors.lastname: He
authors.forename: Peiming
authors.initials: P
authors.lastname: Zhang
authors.forename: Brett
authors.initials: B
authors.lastname: Gyarfas
authors.forename: Stuart
authors.initials: S
authors.lastname: Lindsay
mesh_terms: D004566:Electrodes; D007093:Imidazoles / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D017422:Sequence Analysis, DNA / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: C568937:4(5)-(2-mercaptoethyl)-1H-imidazole-2-carboxamide; D007093:Imidazoles; D013438:Sulfhydryl Compounds