Organic topological insulators in organometallic lattices

Abstract

Topological insulators are a recently discovered class of materials having insulating bulk electronic states but conducting boundary states distinguished by nontrivial topology. So far, several generations of topological insulators have been theoretically predicted and experimentally confirmed, all based on inorganic materials. Here, based on first-principles calculations, we predict a family of two-dimensional organic topological insulators made of organometallic lattices. Designed by assembling molecular building blocks of triphenyl-metal compounds with strong spin-orbit coupling into a hexagonal lattice, this new classes of organic topological insulators are shown to exhibit nontrivial topological edge states that are robust against significant lattice strain. We envision that organic topological insulators will greatly broaden the scientific and technological impact of topological insulators.

Edge states in graphene-like systems

“…(6,7)) as well as the mean field Hubbard terms in the non-collinear approximation (eqs. (10,11) ). The code is available online 60 and has a graphical user interface that permits a simple use by non-experts.…”

“…An incomplete list of graphene-like materials includes Silicene 7 , Germanene 8 , Stanene 9 , Metallic organic framework 10 , hydrogenated Bi(111) 11 , and artificial graphene lattices 12 .…”

Robustness of two-dimensional topological insulator states in bilayer bismuth against strain and electrical field

“…In our study, the direction of the electric field was chosen to be perpendicular to Bi-BL sheet (along the z direction), and the vacuum layer is ~15Å thick. The edge states of 1D zigzag BL-Bi nanoribbon (ZBNR) were calculated as before 20,21 by using the Wannier90 package. 22 The tight-binding Hamiltonian with maximally localized Wannier functions (MLWFs) was fitted to the first-principles calculations.…”

Exotic conductors from lab and nature

“…His team recently proposed a design for such a compound 5 , and says that another group has synthesized a candidate structure. "Ultimately, these will be these cheapest and most versatile materials to work with. "…”