It was impossible to see the edge-states of a graphene nano-ribbon until now. Before, only theoretical predictions could be made. Michael Crommie, of Berkeley Lab's Materials Sciences Division and UC Berkeley's Physics Division, used a scanning tunneling microscope on specially made graphene nano-ribbons and confirmed all the theoretical predications. The results of his research could lead to faster electronics, energy efficient nano-devices from these graphene nano-ribbons. More remarkable, electron charge and spin can be controlled at the edge-states. (See spintronics)
Using a special chemical process, graphene nano-tubes can be cut, un-zipped, in such a way that raised edges can be produced, also known as are-chair edges. It is at these scalloped edges that new potentials can be exploited. Crommie explains, "Two-dimensional graphene sheets are remarkable in how freely electrons move through them, including the fact that there's no band gap. Nanoribbons are different: electrons can become trapped in narrow channels along the nanoribbon edges. These edge-states are one-dimensional, but the electrons on one edge can still interact with the edge electrons on the other side, which causes an energy gap to open up... We might also imagine spintronics applications, where using a side-gate geometry would allow control of the spin polarization of electrons at a nanoribbon's edge."
Controlling the edges is key to this discovery. The next step for Crommie and his team is to reproduce the arm-chair edges at a larger scale. As well as continuing the validation. Read more here.
Eavesdropper
