Andrea C. Ferrari1, Jannik C. Meyer2, Vittorio Scardaci1, Cinzia Casiraghi1, Michele Lazzeri3, Francesco Mauri3, S. Piscanec1, Da Jiang4, Kostya S. Novoselov4, S. Roth2, A. K. Geǐm4
1Cambridge University, Engineering Department, JJ Thompson Avenue, Cambridge CB3 0FA, United Kingdom.
2Max-Planck-Institute for Solid State Research Stuttgart 70569 Germany
3IMPMC, Universites Paris 6 et 7, CNRS, IPGP, 140 rue de Lourmel, 75015 Paris, France
4Department of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom