title: Tuning the bipolar conductance of an alkali-doped C(60) layer sandwiched between two tunneling barriers.
abstract: Resonant tunneling through a C(60) monolayer doped with single Na, K, Rb, and Cs atoms was measured between the tip of a scanning tunneling microscope and a NiAl(110) substrate. By supporting the monolayer on a thin aluminum oxide film grown on the substrate, a double barrier tunnel junction is formed, consisting of the vacuum and oxide. This geometry enables conductance through an electronic state of the alkali-C(60) complex at both positive and negative sample bias. The positions of the conductance peaks can be varied by tuning the vacuum barrier. An opposite variation is found for Na and K as compared to Rb and Cs, suggesting the influence of bonding on nanoscale transport.
authors.affiliation: Department of Physics and Astronomy and Department of Chemistry, University of California, Irvine, California 92697-4575, USA.
authors.forename: Nilay A
authors.initials: NA
authors.lastname: Pradhan
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.forename: Christophe
authors.initials: C
authors.lastname: Silien
authors.forename: Wilson
authors.initials: W
authors.lastname: Ho