2010/01/31 by Wen-Yu Shan, Hai-Zhou Lu, Hai‐Zhou Lu +1 · 9 citations
Materials Science · Physics and Astronomy · #Condensed matter physics #Geometry #Graphene research and applications #Physics #Quantum many-body systems #Surface (topology) #Surface states #Theoretical physics #Topological Materials and Phenomena #Topological insulator #Topology (electrical circuits) #cond-mat.mes-hall
paper · pdf · doi:10.1088/1367-2630/12/4/043048
published as New J. Phys. 12 043048 (2010 ) · 12 pages, 7 figures, references are updated
arxiv created 2010/03/19 · openalex publication_date 2010/04/28 · arxiv updated 2010/04/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Two-dimensional (2D) effective continuous models are derived for the surface states and thin films of a three-dimensional topological insulator (3DTI). Starting from an effective model for 3DTI based on first-principles calculations (Zhang et al 2009 Nat. Phys. 5 438), we present solutions for both the surface states in a semi-infinite boundary condition and those in a thin film with finite thickness. The coupling between opposite topological surfaces and structure inversion asymmetry (SIA) gives rise to gapped Dirac hyperbolas with Rashba-like splittings in the energy spectrum. In addition, SIA leads to asymmetric distributions of wavefunctions for the surface states along the film growth direction, making some branches in the energy spectra much harder than others to probe by light. These features agree well with the recent angle-resolved photoemission spectra of Bi 2 Se 3 films grown on SiC substrate (Zhang et al 2009 arXiv:0911.3706). More importantly, using the parameters fitted by experimental data, the result indicates that the thin film Bi 2 Se 3 lies in the quantum spin Hall (QSH) region based on the calculation of the Chern number and Z 2 invariant. In addition, strong SIA always tends to destroy the QSH state.