Topological Insulator to Dirac Semimetal Transition Driven by Sign Change of Spin-Orbit Coupling in Thallium Nitride

Abstract

Based on the first-principles calculations, we reveal that TlN, a simple binary compound with Wurtzite structure, is a three-dimensional (3D) topological insulator (TI) with effectively negative spin-orbit coupling ${\lambda }_{eff}<0$, which makes it distinguished from other TIs by showing opposite spin-momentum locking effect in its surface states. The sign of ${\lambda }_{eff}$ depends on the hybridization between N-$2p$ and Tl-$5d$ states, and can be tuned from negative to postive by lattice strain or chemical substitution, which drive the system into a Dirac semimetal with 3D Dirac cones in its bulk states. Such topological phase transition can be realized by electronic mechanism without breaking any crystal symmetry.

7 pages, 8 figures, including 2 pages and 4 figures for Supplemental Material

References in corpus (6)

• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Topological Insulators with Inversion Symmetry
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Computing topological invariants without inversion symmetry
• Exploration and prediction of topological electronic materials based on first-principles calculations
• Topological tuning in three-dimensional Dirac semimetals

Cited by in corpus (7)

• Hybrid Dirac Semimetal in CaAgBi Materials Family
• From Type-II Triply Degenerate Nodal Points and Three-Band Nodal Rings to Type-II Dirac Points in Centrosymmetric Zirconium Oxide
• Emergence of Topological Nodal Lines and Type II Weyl Nodes in Strong Spin--Orbit Coupling System InNbX2(X=S,Se)
• Graphdiyne Nanoribbons with Open Hexagonal Rings: Existence of Topological Unprotected Edge States
• Spin- and angle-resolved photoemission on the topological Kondo Insulator candidate: SmB6
• From Multiple Nodal Chain to Dirac/Weyl Semimetal and Topological Insulator in Ternary Hexagonal Materials
• Nonequilibrium topological spin textures in momentum space