Tuning the bipolar conductance of an alkali-doped C(60) layer sandwiched between two tunneling barriers.
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.
Pradhan
Nilay A
NA
Department of Physics and Astronomy and Department of Chemistry, University of California, Irvine, California 92697-4575, USA.
Liu
Ning
N
Silien
Christophe
C
Ho
Wilson
W