  The state of vanishing friction known as superlubricity has important
applications for energy saving and increasing the lifetime of devices.
Superlubricity detected with atomic force microscopy appears in examples like
sliding large graphite flakes or gold nanoclusters across surfaces. However,
the origin of the behavior is poorly understood due to the lack of a
controllable nano-contact. We demonstrate graphene nanoribbons superlubricity
when sliding on gold with a joint experimental and computational approach. The
atomically well-defined contact allows us to trace the origin of
superlubricity, unravelling the role played by edges, surface reconstruction
and ribbon elasticity. Our results pave the way to the scale-up of
superlubricity toward the realization of frictionless coatings.
