2011/07/31 by Paolo Michetti, Jan Carl Budich, Jan C. Budich +3 · 1 citation
Materials Science · Physics and Astronomy · #Bilayer graphene #Condensed matter physics #Degeneracy (biology) #Geometry #Graphene #Graphene research and applications #Magnetic field #Physics #Quantum #Quantum Hall effect #Quantum and electron transport phenomena #Quantum mechanics #Quantum spin Hall effect #Quantum well #Spin (aerodynamics) #Symmetry (geometry) #Topological Materials and Phenomena #Topological insulator #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.85.125309
published as Physical Review B 85, 125309 (2012) · 9 pages, 8 figures, extended version (accepted Phys. Rev. B)
arxiv created 2012/03/13 · openalex publication_date 2012/03/19 · arxiv updated 2012/03/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The field of topological insulators (TIs) is rapidly growing. Concerning possible applications, the search for materials with an easily controllable TI phase is a key issue. The quantum spin Hall effect, characterized by a single pair of helical edge modes protected by time-reversal symmetry, has been demonstrated in HgTe-based quantum wells (QWs) with an inverted band gap. We analyze the topological properties of a generically coupled HgTe-based double QW and show how in such a system a TI phase can be driven by an interlayer bias voltage, even when the individual layers are noninverted. We argue that this system allows for (layer-)pseudospin-based physics similar to that in bilayer graphene but with the crucial absence of a valley degeneracy.