Quantum Spin Hall States in Stanene/Ge(111)

Abstract

For topological insulators to be implemented in practical applications, it is a prerequisite to select suitable substrates that are required to leave insulators’ nontrivial properties and sizable opened band gaps (due to spin-orbital couplings) unaltered. Using ab initio calculations, we predict that Ge(111) surface qualified as a candidate to support stanene sheets, because the band structure of √3 × √3 stanene/Ge(111) (2 × 2) surface displays a typical Dirac cone at Γ point in the vicinity of the Fermi level. Aided with the result of Z2 invariant calculations, a √3 × √3 stanene/Ge(111) (2 × 2) system has been proved to sustain the nontrivial topological phase, with the prove being confirmed by the edge state calculations of stanene ribbons. This finding can serve as guidance for epitaxial growth of stanene on substrate and render stanene feasible for practical use as a topological insulator.

The electronic properties of the stanene/MoS2 heterostructure under strain

“…Ethynyl derivative-functionalized stanene (SnC 2 X: X ¼ H, F, Br, and I) has been studied by Zhang et al 15 Recently, it was found that the strong interaction with the substrate can disturb the Dirac cones. 16 The H-BN 17 and Ge (1 1 1) substrates 18 will induce a band gap in stanene, transforming it into a quantum spin Hall phase.…”

Large area planar stanene epitaxially grown on Ag(1 1 1)

“…First principle calculations suggest that a silver (1 1 1) surface could be also an ideal candidate for growing large-area, high-quality monolayer stanene [12]. Unique physical properties for stanene have been predicted, such as the QSH effect [13,14], topological superconductivity [15], giant magnetoresistance [16], perfect spin filter [16], and anomalous Seebeck effect [17]. All these properties are based on low-buckled stanene.…”

Deposition of topological silicene, germanene and stanene on graphene-covered SiC substrates

“…Graphene-like group-IV, such as silicene 1 – 3 , germanene 1 , 4 , 5 , and stanene 6 , 7 , with two-dimensional (2D) honeycomb geometry have attracted much attention in recent years due to their exotic properties 8 – 11 . Their low-buckled geometries with a mixing of and hybrids but the same lateral symmetry as graphene (Gr) are responsible for extraordinary electronic and optical properties 1 , 8 , e.g., the appearance of Dirac cones near the K corner points of the hexagonal Brillouin zone (BZ).…”