Theme: Topological Material Design
Speaker: Rui Yu, Professor
Host: Wu Li, research scientist
Time: 10:00, December 25th, 2018
Location: Conference Room 103, Office Building
Talk Abstract:
The Dirac, Weyl and Nodal-line states have attracted great research interest in condensed matter physics and material science. In this talk, I will introduce two works on topological semimetals. (1) Based on first-principles calculations and symmetry analysis, we report that Ag2S with P212121 symmetry is a topological Dirac semimetal in the absence of spin-orbit coupling (SOC). Every Dirac points are composed of two Weyl points with the same chirality overlapping in the momentum space. After taking the SOC into consideration, each Dirac point is split into two Weyl points and lead to long Fermi-arcs on material surface. (2) We introduce a scheme to realize topological nodal states with a three-dimensional periodic inductor-capacitor (LC) circuit lattice, where the topological nodal line state and Weyl state can be achieved by tuning the parameters of inductors and capacitors. The key characters of the topological states, such as the drumhead-like surface bands for nodal line state and the Fermi arc-like surface bands for Weyl state, are found in these systems.
About the Speaker:
Prof. Rui Yu graduated from Institute of Physics, Chinese Academy of Sciences with a Ph. D degree in 2011 and carried out postdoctoral research in Hongkong and Japan from 2011 to 2015. He currently works as professor at School of Physics and Technology, Wuhan University. Prof. Yu mainly studies on first-principles calculation and theoretical study of materials, including topological material state, new functional materials. He has published 20 papers, with 3,000 citations.
