Planar bridging an atomically precise surface trench with a single molecular wire on an Au(111) surface

TL;DR

This study demonstrates precise placement of a graphene nanoribbon across an Au(111) surface trench, revealing how contact-induced deformation affects electronic delocalization, with implications for nanoscale device design.

Contribution

It introduces a method for positioning a single GNR with atomic precision over a surface trench and analyzes the impact of contact curvature on electronic properties.

Findings

GNR can be positioned with picometer precision over a surface trench.

Contact curvature deforms the GNR and cuts electronic delocalization.

Proper contact design can preserve GNR's electronic properties.

Abstract

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.