Solid-State and Nano Seminar
Electronic States of the Moiré Superlattice
Two-dimensional (2D) van der Waals (vdW) heterostructures have attracted great attention in the past five years. By stacking different 2D materials to bond via the vdW force, these artificial heterostructures provide interesting and new material phase space for exploration. In this talk I shall focus on one aspect of the 2D vdW materials: the Moiré pattern. In visual arts, Moiré pattern is an optical perception of a new pattern formed on top of two similar stacking patterns. In 2D vdW heterostructures, Moiré pattern can be a physical superlattice which brings about novel electronic properties. I shall present and discuss some of the calculated novel properties of the Moiré superlattice: the emergence of a secondary Dirac cone, the suppression of the carrier mobility at some "magic angles", and the formation of multiple helical valley currents, on various 2D vdW heterostructure materials. Some of these properties can well be the basis of interesting applications.
Hong Guo obtained B.Sc. in Physics at the Sichuan Normal University in China and Ph.D. in theoretical condensed matter physics at the University of Pittsburgh. He joined McGill University in 1989 and is currently a James McGill Professor of Physics. His research includes quantum transport theory, nanoelectronic device physics, materials physics, mathematical and computational physics. He was elected to Fellow of the American Physical Society in 2004, and Fellow of the Royal Society of Canada in 2007. He received the Killam Research Fellowship Award from the Canadian Council for the Arts in 2004; the Brockhouse Medal for Excellence in Experimental or Theoretical Condensed Matter Physics of the Canadian Association of Physicists in 2006; and the CAP-CRM Prize in Theoretical and Mathematical Physics from Canadian Association of Physicists in 2009.