Topological Dirac line nodes in centrosymmetric semimetals

Dr. Youngkuk Kim, University of Pennsylvania
Nov. 6 (Fri), 16:30 PM,  #5318(E6-2)

Dirac line nodes (DLNs) are one-dimensional Dirac nodes of energy manifolds in momentum space. In the presence of inversion symmetry and time-reversal symmetry, crystals with vanishing spin-orbit coupling can host topologically protected DLNs.

Recently, we have proposed and characterized a novel Z2 class of the DLN semimetals [1]. Z2 topological invariants, dictating the presence of DLNs, are developed based on the parity eigenvalues at the parity-invariant points of reciprocal space. Our first-principles calculations show that DLN semimetals can be realized in Cu3N in anti-ReO3 structure via metal-insulator electronic transition, driven by transition metal doping. We will also discuss the surface consequence and the effect of spin-orbit coupling of DLN materials.
[1] Youngkuk Kim, Benjamin J. Wieder, C. L. Kane, and Andrew M. Rappe, Phys. Rev. Lett. 115, 036806 (2015)

Contact: MyungJoon Han, Physics Dept., (mj.han@kaist.ac.kr)