A robust weak topological insulator in a bismuth halide Bi4Br2I2

Abstract

We apply a topological material design concept for selecting a bulk topology of 3D crystals by different van-der-Waals stacking of 2D topological insulator layers, and find a bismuth halide Bi4Br2I2 to be an ideal weak topological insulator (WTI) with the largest band gap (~230 meV) among all the WTI candidates, by means of angle-resolved photoemission spectroscopy (ARPES), density functional theory (DFT) calculations, and resistivity measurements. Our results vastly expand future opportunities for fundamental research and device applications with a robust WTI.

7 pages, 4 figures

References in corpus (10)

• Topological Insulators with Inversion Symmetry
• Stacked topological insulator built from bismuth-based graphene sheet analogues
• Large-Gap Quantum Spin Hall Insulator in single layer bismuth monobromide Bi${}_4$Br${}_4$
• Prediction of weak topological insulators in layered semiconductors
• Purely rotational symmetry-protected topological crystalline insulator $\alpha$-Bi4Br4
• Topological edge states in single- and multi-layer Bi${}_4$Br${}_4$
• Room-Temperature Topological Phase Transition in Quasi-One-Dimensional Material Bi${}_4$I${}_4$
• Quantum transport properties of beta-Bi4I4 near and well beyond the extreme quantum limit
• Optical bulk-boundary dichotomy in a quantum spin Hall insulator
• Quantum transport evidence of the boundary states and Lifshitz transition in Bi${}_4$Br${}_4$

Cited by in corpus (2)

• Altermagnetism-Induced Parity Anomaly in Weak Topological Insulators
• Phonons Drive the Topological Phase Transition in Quasi-One-Dimensional Bi${}_4$I${}_4$