Transport discovery of emerging robust helical surface states in $Z_2=0$ systems

Abstract

We study the possibility of realizing robust helical surface states in $Z_2=0$ systems. We find that the combination of anisotropy and finite-size confinement leads to the emergence of robust helical edge states in both 2D and 3D $Z_2=0$ systems. By investigating an anisotropic Bernevig-Hughes-Zhang model in a finite sample, we demonstrate that the transport manifestation of the surface states is robust against non-magnetic disorder, resembling that of a $Z_2=1$ phase. Notably, the effective energy gap for the robust helical states can be efficiently engineered, allowing for potential applications as valley filters and valley valves. The realization of emerging robust helical surface states in realistic material is also discussed.

5 pages, 4 figures; submitted to Phys. Rev. Lett. on Nov. 25. 2013

References in corpus (16)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Topological Insulators with Inversion Symmetry
• Topological Crystalline Insulators
• Valley filter and valley valve in graphene
• First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
• Topological Surface States Protected From Backscattering by Chiral Spin Texture
• Nonlocal edge state transport in the quantum spin Hall state
• Quantum Spin Hall Effect and Topologically Invariant Chern Numbers
• Gate-Voltage Control of Chemical Potential and Weak Anti-localization in Bismuth Selenide
• Finite size effects of helical edge states in HgTe/CdTe quantum wells
• Momentum-Resolved Landau-Level Spectroscopy of Dirac Surface State in Bi2Se3
• Stacked topological insulator built from bismuth-based graphene sheet analogues
• The dependence of topological Anderson insulator on the type of disorder
• Prediction of weak topological insulators in layered semiconductors
• Finite-size energy gap in weak and strong topological insulators

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• Edge states in proximitized graphene ribbons and flakes in a perpendicular magnetic field: emergence of lone pseudohelical pairs and pure spin-current states
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• Stability of the X-Y-phase of the two-dimensional C4 point group insulator