Ballistic transport could spawn new devices, says research team

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Research conducted by Georgia Tech and its partners shows that electrical resistance in nanoribbons of epitaxial graphene changes in discrete steps following quantum mechanical principles.

According to the team, its work also shows that graphene nanoribbons act more like optical waveguides or quantum dots, allowing electrons to flow smoothly along the edges of the material. Using electrons more like photons could enable a new type of electronic device that would capitalise on the ability of graphene to carry electrons with almost no resistance, even at room temperature – a property known as ballistic transport. "This work shows that we can control graphene electrons in very different ways because the properties are really exceptional," said Professor Walt de Heer from Georgia Tech's School of Physics. "This could result in a new class of coherent electronic devices based on room temperature ballistic transport in graphene. Such devices would be very different from what we make today in silicon." The ballistic transport properties were measured in graphene nanoribbons approximately 40nm wide that had been grown on the edges of 3D structures etched into silicon carbide wafers. Prof de Heer argues that researchers should stop trying to use graphene like silicon and instead use its unique electron transport properties to design new types of electronic devices that could allow ultra fast computing. "This should enable a new way of doing electronics," he concluded. "We are already able to steer these electrons and we can switch them using rudimentary means. We can put a roadblock, and then open it up again. New kinds of switches for this material are now on the horizon." The research was done through a collaboration of scientists from Georgia Tech, Leibniz Universität Hannover, the Centre National de la Recherche Scientifique in France and the US Oak Ridge National Laboratory.