title: Intrinsic Two-Dimensional Organic Topological Insulators in Metal-Dicyanoanthracene Lattices.
abstract: We predict theoretical existence of intrinsic two-dimensional organic topological insulator (OTI) states in Cu-dicyanoanthracene (DCA) lattice, a system that has also been grown experimentally on Cu substrate, based on first-principle density functional theory calculations. The pz-orbital Kagome bands having a Dirac point lying exactly at the Fermi level are found in the freestanding Cu-DCA lattice. The tight-binding model analysis, the calculated Chern numbers, and the semi-infinite Dirac edge states within the spin-orbit coupling gaps all confirm its intrinsic topological properties. The intrinsic TI states are found to originate from a proper number of electrons filling of the hybridized bands from Cu atomic and DCA molecular orbitals based on which similar lattices containing noble metal atoms (Au and Cu) and those molecules with two CN groups (DCA and cyanogens) are all predicted to be intrinsic OTIs.
authors: Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China , Chengdu 610054, China.|Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.|Department of Materials Science and Engineering, University of Utah , Salt Lake City, Utah 84112, United States.
authors: L Z
authors: LZ
authors: Zhang
authors: Department of Materials Science and Engineering, University of Utah , Salt Lake City, Utah 84112, United States.|Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China.
authors: Z F
authors: ZF
authors: Wang
authors: Department of Materials Science and Engineering, University of Utah , Salt Lake City, Utah 84112, United States.
authors: B
authors: B
authors: Huang
authors: Department of Materials Science and Engineering, University of Utah , Salt Lake City, Utah 84112, United States.
authors: B
authors: B
authors: Cui
authors: Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China , Chengdu 610054, China.
authors: Zhiming
authors: Z
authors: Wang
authors: Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors: S X
authors: SX
authors: Du
authors: Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors: H-J
authors: HJ
authors: Gao
authors: Department of Materials Science and Engineering, University of Utah , Salt Lake City, Utah 84112, United States.|Collaborative Innovation Center of Quantum Matter, Beijing 100084, China.
authors: Feng
authors: F
authors: Liu
keywords: Dirac band; Topological insulator; flat band; intrinsic; organometallic framework