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arXiv · 2301.07158

A robust weak topological insulator in a bismuth halide Bi4Br2I2

Ryo Noguchi·Masaru Kobayashi·Kaishu Kawaguchi·Chun Lin·Hiroaki Tanaka·Kenta Kuroda·Ayumi Harasawa·Viktor Kandyba·Mattia Cattelan·Alexei Barinov·Makoto Hashimoto·Donghui Lu·Takao Sasagawa·Takeshi Kondo
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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.

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Ryo Noguchi, Masaru Kobayashi, Kaishu Kawaguchi, Chun Lin, Hiroaki Tanaka, Kenta Kuroda, Ayumi Harasawa, Viktor Kandyba, Mattia Cattelan, Alexei Barinov, Makoto Hashimoto, Donghui Lu, Takao Sasagawa, Takeshi Kondo. 2023-01-17. A robust weak topological insulator in a bismuth halide Bi4Br2I2. https://doi.org/10.1103/physrevlett.133.086602

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