Department of Micro- and Nanotechnology, Technical University of Denmark  Being a high mobility and ambipolar conductor, graphene has been proposed to replace and complement a broad range of electronic devices including high-frequency communication devices or photodetectors [1].However, graphene unique properties involving the relativistic character of its charge carriers are rarely utilized, specifically at application-relevant conditions. In particular, the presence of negative refraction of Dirac fermions in graphene [2] is of particular relevance to develop novel quantum devices based on electron optics. The present work addresses the guidance of relativistic carriers by employing periodic potential modulation (np junctions); demonstrated by the anisotropic propagation of charge carriers in these systems. Guiding effects survive even at ambient conditions, crucial for the technological development of novel electronic systems based on Dirac-fermions. [1] Palacios, T. Graphene electronics: Thinking outside the silicon box. Nature Nanotech. 6, 464 (2011). [2] Lee, G-H.; Park, G-H.& Lee. H-J. Observation of negative refraction of Dirac fermions in graphene. Nature Physics, 11, 925  José Caridad is currently a postdoctoral researcher at the Technical University of Denmark. He is primarily interested in the optical and electronic properties of low dimensional systems such as graphene. His research focuses not only in understanding the fundamental properties of these devices, but also their industrial scalability and performance at application-relevant conditions. He received his BSc and MSc degrees in Physics from the University of Salamanca (2008) and a PhD in Physics (2014) from Trinity College Dublin. |