  Atomically precise graphene nanoribbons (GNRs) are predicted to exhibit
exceptional edge-related properties, such as localized edge states, spin
polarization, and half-metallicity. However, the absence of low-resistance
nano-scale electrical contacts to the GNRs hinders harnessing their properties
in field-effect transistors. In this paper, we make electrical contact with
9-atom-wide armchair GNRs using superconducting alloy MoRe as well as Pd (as a
reference), which are two of the metals providing low-resistance contacts to
carbon nanotubes. We take a step towards contacting a single GNR by fabrication
of electrodes with a needle-like geometry, with about 20 nm tip diameter and 10
nm separation. To preserve the nano-scale geometry of the contacts, we develop
a PMMA-assisted technique to transfer the GNRs onto the pre-patterned
electrodes. Our device characterizations as a function of bias-voltage and
temperature, show a thermally-activated gate-tunable conductance in the
GNR-MoRe-based transistors.
