Home >  研究会等 > Anomalous crystal shapes of topological materials

Anomalous crystal shapes of topological materials

日程 : 2024年7月16日(火) 2:45 pm - 3:45 pm 場所 : 物性研究所本館6階 第5セミナー室 (A615)、および zoom(ハイブリッド) 講師 : 田中 悠太朗 所属 : 国立研究開発法人理化学研究所 創発物性科学研究センター 世話人 : 川畑 幸平講演言語 : 英語

Understanding crystal shapes is a fundamental subject in surface science. It is now well-studied how chemical bondings determine crystal shapes via the dependence of surface energies on surface orientations. Meanwhile, discoveries of topological materials have led us to a new paradigm in surface science, and one can expect that topological surface states may affect surface energies and crystal facets in an unconventional way.

In this talk, we show that the surface energy of glide-symmetric topological crystalline insulators (TCI) depends on the surface orientation in a singular way via the parity of the Miller index. This singular surface energy of the TCI affects equilibrium crystal shapes, resulting in the emergence of unique crystal facets of the TCI [1]. Furthermore, we study the equilibrium crystal shapes of a topological insulator (TI), a TCI protected by mirror symmetry, and a second-order topological insulator (SOTI) protected by inversion symmetry. In terms of the calculations of the simple tight-binding model, we show that the various boundary states of the TI, TCI, and SOTI affect the emergence of the specific facets [2].

[1] Y. Tanaka, T. Zhang, M. Uwaha, and S. Murakami, Phys. Rev. Lett. 129, 046802 (2022).
[2] Y. Tanaka and S. Murakami, Phys. Rev. B 107, 245148 (2023).

Registration: https://forms.gle/7gCTd7DWbgaDUCuX9

(公開日: 2024年07月04日)