Two-Dimensional Group-IV Chalcogenide Si2Te2 film: A New Quantum Spin Hall Insulator with Sizable Band Gap
arXiv:1607.02973 · doi:10.1063/1.4966124
Abstract
Quantum spin Hall (QSH) effect is promising for achieving dissipationless transport devices due to the robust gapless states inside insulating bulk gap. Here, by using first-principles calculations, we discover group-IV chalcogenide Si2Te2 film to be a 2D QSH insulator with a fundamental band gap of 0.29 eV, which is tunable under external strain. This nontrivial topological phase stems from band inversion between the Si-px,y and Te-px,y orbitals, demonstrated by a single pair of topologically protected helical edge states with Dirac point locating in the bulk gap. Notably, the characteristic properties of edge states, such as the Fermi velocity and edge shape, can be tuned by edge modifications. Additionally, the h-BN semiconductor is an ideal substrate for experimental realization of 2D Si2Te2 film, without destroying its nontrivial topology. Our works open a new route for designing topological spintronics devices based on 2D silicon-based films.
arXiv comment18 pages, 6 figures
References in corpus (18)
- Topological insulators and superconductors
- Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
- Topological Order and the Quantum Spin Hall Effect
- Quantum Spin Hall Insulator State in HgTe Quantum Wells
- Van der Waals density functionals applied to solids
- Wannier90: A Tool for Obtaining Maximally-Localised Wannier Functions
- Quantum Spin Hall Effect in Silicene
- Low-energy effective Hamiltonian involving spin-orbit coupling in Silicene and Two-Dimensional Germanium and Tin
- Large-gap quantum spin Hall insulators in tin films
- Quantum Spin Hall Effect in Inverted Type II Semiconductors
- Observation of Quantum Spin Hall States in InAs/GaSb Bilayers under Broken Time-Reversal Symmetry
- Well-localized edge states in two-dimensional topological insulators: ultrathin Bi films
- Epitaxial growth of large-gap quantum spin Hall insulator on semiconductor surface
- Large-Gap Quantum Spin Hall States in Stanene Grown on Substrate
- Majorana Fermions: The race continues
- Tunable Quantum Spin Hall Effect via Strain in two-Dimensional Arsenene Monolayer
- Functionalized Thallium Antimony Films as Excellent Candidates for Large-Gap Quantum Spin Hall Insulator
- Robust Room-Temperature Quantum Spin Hall Effect in Methyl-functionalized InBi honeycomb film
Cited by in corpus (9)
- Two-Dimensional Arsenene Oxide: A Realistic Large-gap Quantum Spin Hall Insulator
- Discovery of Intrinsic Quantum Anomalous Hall Effect in Organic Mn-DCA Lattice
- New Families of Large Band Gap 2D Topological Insulators in Ethynyl-Derivative Functionalized Compounds
- Quantization of spin Hall conductivity in two-dimensional topological insulators versus symmetry and spin-orbit interaction
- Two-Dimensional Large Gap Topological Insulators with Large Rashba Spin-Orbit Coupling in Group-IV films
- Two-dimensional Janus Si dichalcogenides: A first-principles study
- Prediction of Topological Crystalline Insulator and Topological Phase Transitions in Two-dimensional PbTe Films
- Prediction of half-metallic properties in TlCrS2 and TlCrSe2 based on density functional theory
- Semimetal behavior of bilayer stanene