Graphene is a two dimensional material consisting of a single layer of carbon atoms arranged in a honeycomb or chicken wire structure. It is the thinnest material known and yet is also one of the strongest. It conducts electricity as efficiently as copper and outperforms all other materials as a conductor of heat. Previous studies have demonstrated that carbon nanotube has excellent electrical properties, but is difficult to be installed into the electronic chips due to its complex structure. Therefore, researchers turned to study another form of graphene - a flat graphene nanoribbon.

Graphene nanoribbons will be essential components in future graphene nanoelectronics. However, in typical nanoribbons produced from lithographically patterned exfoliated graphene, the charge carriers travel only about ten nanometres between scattering events, resulting in minimum sheet resistances of about one kilohm per square. Here they show that 40-nanometre-wide graphene nanoribbons epitaxially grown on silicon carbide are single-channel room-temperature ballistic conductors on a length scale greater than ten micrometres, which is similar to the performance of metallic carbon nanotubes. This is equivalent to sheet resistances below 1 ohm per square, surpassing theoretical predictions for perfect graphene8 by at least an order of magnitude. In neutral graphene ribbons, they show that transport is dominated by two modes. One is ballistic and temperature independent; the other is thermally activated. Transport is protected from back-scattering, possibly reflecting ground-state properties of neutral graphene. At room temperature, the resistance of both modes is found to increase abruptly at a particular length—the ballistic mode at 16 micrometres and the other at 160 nanometres. Their epitaxial graphene nanoribbons will be important not only in fundamental science, but also—because they can be readily produced in thousands—in advanced nanoelectronics, which can make use of their room-temperature ballistic transport properties.(Nature, 2014, doi:10.1038/nature12952)

Graphene has already earned its discoverers a Nobel Prize, but its true promise is only beginning to be realized, especially for its practical applications. Graphene nanoribbons could be capable of transporting electrons thousands of times faster than a traditional metallic conductor. Transistors based on nanoribbons could also be packed very close together — a human hair is 10,000 times wider than Fischer’s nanoribbons. Thus, a chip based on graphene nanoribbons could have a huge number of very fast transistors that dissipate heat more efficiently than metal. If the process is perfected and scaled up, graphene nanoribbons could allow all electronic circuits to be improved dramatically. Everything from CPUs to storage technology could get faster, and Moore’s Law might have a future after all.