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arXiv · 2308.00999

Broken Screw Rotational Symmetry in the Near-Surface Electronic Structure of $AB$-Stacked Crystals

Hiroaki Tanaka·Shota Okazaki·Masaru Kobayashi·Yuto Fukushima·Yosuke Arai·Takushi Iimori·Mikk Lippmaa·Kohei Yamagami·Yoshinori Kotani·Fumio Komori·Kenta Kuroda·Takao Sasagawa·Takeshi Kondo
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Abstract

We investigate the electronic structure of $2H$-$\mathrm{Nb}\mathrm{S}_2$ and $h$-$\mathrm{BN}$ by angle-resolved photoemission spectroscopy (ARPES) and photoemission intensity calculations. Although in bulk form, these materials are expected to exhibit band degeneracy in the $k_z=\pi/c$ plane due to screw rotation and time-reversal symmetries, we observe gapped band dispersion near the surface. We extract from first-principles calculations the near-surface electronic structure probed by ARPES and find that the calculated photoemission spectra from the near-surface region reproduce the gapped ARPES spectra. Our results show that the near-surface electronic structure can be qualitatively different from the bulk one due to partially broken nonsymmorphic symmetries.

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Hiroaki Tanaka, Shota Okazaki, Masaru Kobayashi, Yuto Fukushima, Yosuke Arai, Takushi Iimori, Mikk Lippmaa, Kohei Yamagami, Yoshinori Kotani, Fumio Komori, Kenta Kuroda, Takao Sasagawa, Takeshi Kondo. 2023-08-02. Broken Screw Rotational Symmetry in the Near-Surface Electronic Structure of $AB$-Stacked Crystals. https://doi.org/10.1103/physrevlett.132.136402

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