The Coexistence and Decoupling of Bulk and Edge States in Disordered Two-dimensional Topological Insulators

Abstract

We investigate the scattering and localization properties of edge and bulk states in a disordered two-dimensional topological insulator when they coexist at the same fermi energy. Due to edge-bulk backscattering (which is not prohibited \emph{a priori} by topology or symmetry), Anderson disorder makes the edge and bulk states localized indistinguishably. Two methods are proposed to effectively decouple them and to restore robust transport. The first kind of decouple is from long range disorder, since edge and bulk states are well separated in $k$ space. The second one is from an edge gating, owing to the edge nature of edge states in real space. The latter can be used to electrically tune a system between an Anderson insulator and a topologically robust conductor, i.e., a realization of a topological transistor.

5 pages, 4 figures

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Cited by in corpus (6)

• Valley-polarized quantum anomalous Hall phase and disorder induced valley-filtered chiral edge channels
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• Disorder Effects in Topological States -- Brief Review of the Recent Developments
• Single-edge transport in an InAs/GaSb quantum spin Hall insulator
• Chebyshev Polynomial Method to Landauer-Büttiker Formula of Quantum Transport in Nanostructures
• Transport through Quantum Anomalous Hall Bilayers with Lattice Mismatch