2021/03/29 by Mengli Hu, Guofu Ma, Chun Yu Wan +1 · 15 citations
Chemistry · Materials Science · Mathematics · Physics and Astronomy · #2D Materials and Applications #Chemistry #Combinatorics #Condensed matter physics #Coupling (piping) #Crystallography #Electronic band structure #Electronic structure #Energy (signal processing) #Geometry #Graphene research and applications #Homogeneous space #Inverse #Materials science #Mathematics #Physics #Quantum mechanics #Tight binding #Topological Materials and Phenomena #Type (biology) #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.104.035156
published in Physical review. B./Physical review. B 104(3) (American Physical Society)
arxiv created 2021/03/29 · openalex publication_date 2021/07/27 · openalex created_date 2021/08/02 · arxiv updated 2021/08/04 · openalex updated_date 2026/08/05
Monolayer transition metal dichalcogenides MX2 (M=Mo, W and X=Te, Se, S) in 1T^\ensuremath' structure were predicted to be quantum spin Hall insulators based on first-principles calculations, which were quickly confirmed by multiple experimental groups. For a better understanding of their properties, in particular, their responses to external fields, we construct a realistic four-band tight-binding (TB) model by combining the symmetry analysis and first-principles calculations. Our TB model respects all symmetries and can accurately reproduce the band structure in a large energy window from \ensuremath-0.3 eV to 0.8 eV. With the inclusion of spin-orbital coupling (SOC), our TB model can characterize the nontrivial topology and the corresponding edge states. Our TB model can also capture the anisotropic strain effects on the band structure and the strain-induced metal-insulator transition. Moreover, we found that although MX2 share the same crystal structures and have the same crystal symmetries, the orbital composition of states around the Fermi level are qualitatively different and their lower-energy properties cannot be fully described by a single \mathbitk\ifmmode⋅\else\textperiodcentered\fi\mathbitp model. Thus, we construct two different types of \mathbitk\ifmmode⋅\else\textperiodcentered\fi\mathbitp models, one for MS2 and MSe2, the other for MTe2, respectively. Benefiting from high accuracy and simplicity, our TB and \mathbitk\ifmmode⋅\else\textperiodcentered\fi\mathbitp models can serve as a solid and concrete starting point for future studies of transport, superconductivity, strong correlation effects, and twistronics in 1T^\ensuremath' transition metal dichalcogenides.