報告題目：Dirac materials and novel properties in 2D limits

報告人：Liangzhi Kou(寇良志)

報告時間：2017年12月16日（周六）下午3:00

報告地點：化學(xué)樓2樓1號會議室

報告人簡介：Dr. Liangzhi Kou obtained PhD from Nanjing University of Aeronautics and Astronautics in 2011. He has been a visiting scholar at University of Nevada, Las Vegas (UNLV), USA during March 2010 to January 2011. Before he got a faculty position at Queensland University of Technology, Australia since July 2015, he has been an Alexander von Humboldt Research Fellow at University of Bremen and a Postdoctoral Fellow at UNSW, Australia. His research interests include 2D layered materials, semiconductor surface and nanostructures, topological insulators. Up to now, he has published 60 high impact academic papers (including Nano Lett., ACS Nano, Adv.Mater., J. Phys. Chem. Lett.).

報告簡介：Among the huge family of 2D materials, graphene is the superstar due to extremely high carrier mobility, high stable and outstanding mechanical strength. One typical feature of graphene is the linear band dispersion near the Fermi level, which render it possess high Fermi velocity and high carrier mobility. The families with the merit are called as Dirac materials.

     From first principle calculations, we found the recent synthesized boron sheet is the stable Dirac layered materials after surface hydrogenation with high Fermi velocity, and outstanding mechanical properties. More interesting, the sheet simultaneously exhibit the phenomena of negative Poisson ratio, ferroelasticity and Dirac switch, therefore rendering borophane promising in future nanodevice application.

      We also suggested that topological insulators are another family of Dirac materials due to the helical metallic edge states. With the feasible approaches, we turn graphene into strong topological insulators with large nontrivial band gaps, and demonstrated the presence of metallic edge states with 1D Dirac cones.