  In a bridge configuration, a single graphene nanoribbon (GNR) is positioned
with a picometer precision over a trench in between two monoatomic steps on an
Au(111) surface. This GNR molecular wire adopts a deformed conformation towards
the down terrace in between the two contact step edges. Using differential
conductance dI/dV mapping from a low-temperature scanning tunneling microscope,
it is demonstrated how the electronic delocalization along GNR is cut at each
contact by its down curvature. It points out the need to bring conductive
nanocontacts backside of the support for preserving the front side GNR planar
conformation.
