Topological edge states in single- and multi-layer BiBr
arXiv:1409.0943 · doi:10.1088/1367-2630/17/1/015004
Abstract
Topological edge states at the boundary of quantum spin Hall (QSH) insulators hold great promise for dissipationless electron transport. The device application of topological edge states has several critical requirements for the QSH insulator materials, e.g., large band gap, appropriate insulating substrates, and multiple conducting channels. In this paper, based on first-principle calculations, we show that BiBr is a suitable candidate. Single-layer BiBr was demonstrated to be QSH insulator with sizable gap recently. Here, we find that, in multilayer systems, both the band gaps and low-energy electronic structures are only slightly affected by the interlayer coupling. On the intrinsic insulating substrate of BiBr, the single-layer BiBr well preserves its topological edge states. Moreover, at the boundary of multilayer BiBr, the topological edge states stemming from different single-layers are weakly coupled, and can be fully decoupled via constructing a stair-stepped edge. The decoupled topological edge states are well suitable for multi-channel dissipationless transport.
4 pages, 4 figures
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Cited by in corpus (5)
- Optical bulk-boundary dichotomy in a quantum spin Hall insulator
- Effective action approach to the filling anomaly in crystalline topological matter
- Quantum spin Hall phase in multilayer graphene
- Chiral surface states on the step edge in a Weyl semimetal
- Optical Response from Charge-Density Waves in Weyl Semimetals