Topological edge states in single- and multi-layer Bi${}_4$Br${}_4$

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 Bi${}_4$Br${}_4$ is a suitable candidate. Single-layer Bi${}_4$Br${}_4$ 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 Bi${}_4$Br${}_4$, the single-layer Bi${}_4$Br${}_4$ well preserves its topological edge states. Moreover, at the boundary of multilayer Bi${}_4$Br${}_4$, 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.

arXiv comment4 pages, 4 figures

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Cited by in corpus (21)

• Material design with the van der Waals stacking of bismuth-halide chains realizing a higher-order topological insulator
• Room-temperature quantum spin Hall edge state in a higher-order topological insulator Bi${}_4$Br${}_4$
• Weak Topological Insulators and Composite Weyl Semimetals: $\beta$-Bi${}_4$X${}_4$ (X=Br, I)
• Topological electronic structure and spin texture of quasi-one-dimensional higher-order topological insulator Bi4Br4
• Epitaxial Growth of Quasi-One-Dimensional Bismuth-Halide Chains with Topological Non-Trivial Edge States
• Dimensional crossover of transport characteristics in topological insulator nanofilms
• Facet Dependent Topological Phase Transition in Bi4Br4
• Feature-energy duality of topological boundary states in multilayer quantum spin Hall insulator
• Effective action approach to the filling anomaly in crystalline topological matter
• Optical bulk-boundary dichotomy in a quantum spin Hall insulator
• Quantum transport evidence of the boundary states and Lifshitz transition in Bi${}_4$Br${}_4$
• A robust weak topological insulator in a bismuth halide Bi4Br2I2
• Mass Acquisition of Dirac Fermions in Bi4I4 by Spontaneous Symmetry Breaking
• Quantum spin Hall phase in multilayer graphene
• Shear-resistant topology in quasi one-dimensional van der Waals material Bi${}_4$Br${}_4$
• Signature of quantum phase transition manifested in quantum fidelity at finite temperature
• Chiral surface states on the step edge in a Weyl semimetal
• Quantum Coherent Transport of 1D ballistic states in second order topological insulator Bi${}_4$Br${}_4$
• Weak topological insulators with step edges: Subband engineering and its effect on electron transport
• Optical Response from Charge-Density Waves in Weyl Semimetals
• Phonons Drive the Topological Phase Transition in Quasi-One-Dimensional Bi${}_4$I${}_4$