  The conductance of a molecular junction is commonly determined by either
charge-transfer-doping, where alignment of the Fermi energy to the molecular
levels is achieved, or tunnelling through the tails of molecular resonances
within the highest-occupied and lowest-unoccupied molecular-orbital gap.
  Here, we present an alternative mechanism where electron transport is
dominated by electrode surface states. They give rise to metallization of the
molecular bridge and additional, pronounced conductance resonances allowing for
substantial tailoring of its electronic properties via, e.g. a gate voltage.
This is demonstrated in a field-effect geometry of a fullerene-bridge between
two metallic carbon nanotubes.
