Faculty of Engineering and Natural Sciences
Spin currents in rough graphene nanoribbons: Universal fluctuations and spin injection
Institut für Theoretische Physik, Universität Regensburg, Germany
Abstract: In this talk, I will focus on spin transport in graphene, a single atomic layer of graphite, and propose spin injection mechanisms based only on graphitic nanostructures. I will describe how the zero modes localized at the edges of graphene get magnetized and how nanoribbons with asymmetrically shaped edges show a non-zero spin conductance and can be used for spin injection. Furthermore, nanoribbons with rough edges exhibit mesoscopic spin conductance fluctuations with a universal value of $rms G_s\approx 0.4 e/4\pi$, when the localization length is comparable to the length of the ribbon. I will then focus on the universalities featured by the spin currents and show how to describe the fluctuations of the spin currents. Symmetric ribbons, on the other hand, feature a novel spin Hall effect, originating from the novel internal spin-like degree of freedom unique to graphene, which can be used to generate pure spin currents. I will conclude by a discussion of possible experimental setups to detect the spin conductance of graphene nanoribbons.
April 21, 2008, 16:40, FENS G029