Preprint
Kazuma Saito, Ryo Okugawa, Kazuki Yokomizo, Takami Tohyama, and Chen-Hsuan Hsu, "Quasiperiodicity-induced non-Hermitian skin effect from the breakdown of scale-free localization", arXiv:2602.11155.
Papers
Hikaru Goto, Ryo Okugawa, and Takami Tohyama, "Chern insulators and topological flat bands in cavity-embedded kagome systems", Phys. Rev. B 113, 165201 (2026).
Yu-Peng Wang, Chuo-Kai Yang, Ryo Okugawa, and Chen-Hsuan Hsu, "Quasiperiodicity-induced bulk localization with self-similarity in non-Hermitian systems", Phys. Rev. Research 7, 043353(2025).
Yutaro Tanaka, Daichi Nakamura, Ryo Okugawa, and Kohei Kawabata, "Exceptional second-order topological insulators", Phys. Rev. B 112, 245302(2025).
Kazuma Saito, Masahiro Hori, Ryo Okugawa, K. Tanaka, and Takami Tohyama, "Gapless superconductivity and its real-space topology in quasicrystals", Phys. Rev. Research 7, L022077(2025).
Masahiro Hori, Ryo Okugawa, K. Tanaka, and Takami Tohyama, "Weyl superconductivity and quasiperiodic Majorana arcs in quasicrystals", Phys. Rev. Research 6, 033088 (2024).
Yutaro Tanaka, Ryo Takahashi, and Ryo Okugawa, "Non-Hermitian skin effect enforced by nonsymmorphic symmtries", Phys. Rev. B 109, 035131(2024).
Yutaro Tanaka, Ryo Takahashi, Ryo Okugawa, and Shuichi Murakami, “Rotoinversion-symmetric bulk-hinge correspondence and its applications to higher-order Weyl semimetals”, Phys. Rev. B 105, 115119 (2022).
Tsuneya Yoshida, Ryo Okugawa, and Yasuhiro Hatsugai, “Discriminant indicators with generalized inversion symmetry”, Phys. Rev. B 105, 085109 (2022).
Ryo Okugawa, Hiroki Oshiyama, and Masayuki Ohzeki, “Mirror-symmetry-protected dynamical quantum phase transition in topological crystalline insulators”, Phys. Rev. Research 3, 043064 (2021).
Ryo Okugawa, Ryo Takahashi, and Kazuki Yokomizo, “Non-Hermitian band topology with generalized inversion symmetry”, Phys. Rev. B 103, 205205 (2021).
Ryo Okugawa, Ryo Takahashi, and Kazuki Yokomizo, “Second-order topological non-Hermitian skin effects”, Phys. Rev. B 102, 241202(R) (2020).
Ryo Okugawa, Shin Hayashi and Takeshi Nakanishi, “Second-order topological phases protected by chiral symmetry”, Phys. Rev. B 100, 235302 (2019).
Ryo Okugawa and Takehito Yokoyama, “Topological exceptional surfaces in non-Hermitian systems with parity-time and parity-particle-hole symmetries”, Phys. Rev. B 99, 041202(R) (2019). (Editors' Suggestion)
Ryo Okugawa and Takehito Yokoyama, “Generic phase diagram for Weyl superconductivity in mirror-symmetric superconductors”, Phys. Rev. B 97, 060504(R) (2018).
Ryo Okugawa and Shuichi Murakami, “Universal phase transition and band structures for spinless nodal-line and Weyl semimetals”, Phys. Rev. B 96, 115201 (2017).
Shuichi Murakami, Motoaki Hirayama, Ryo Okugawa, and Takeshi Miyake, “Emergence of topological semimetals in gap closing in semiconductors without inversion symmetry”, Science Advances 3, e1602680 (2017).
Motoaki Hirayama, Ryo Okugawa, Takashi Miyake, and Shuichi Murakami, “Topological Dirac Nodal Lines and Surface Charges in fcc Alkaline Earth Metals”, Nat. Commun. 8, 14022 (2017).
Ryo Okugawa, Junya Tanaka, Takashi Koretsune, Susumu Saito, and Shuichi Murakami, “In-plane electric polarization of bilayer graphene nanoribbons by interlayer bias voltage”, Phys. Rev. Lett. 115, 156601 (2015).
Motoaki Hirayama, Ryo Okugawa, Shoji Ishibashi, Shuichi Murakami, and Takashi Miyake, “Weyl Node and Spin Texture in Trigonal Tellurium and Selenium”, Phys. Rev. Lett. 114, 206401 (2015).
Ryo Okugawa and Shuichi Murakami, “Dispersion of Fermi arcs in Weyl semimetals and their evolutions to Dirac cones”, Phys. Rev. B 89, 235315 (2014).
Review
Motoaki Hirayama, Ryo Okugawa and Shuichi Murakami, “Topological Semimetals Studied by Ab Initio Calculations”, J. Phys. Soc. Jpn. 87, 041002 (2018).
Proceedings
Motoaki Hirayama, Ryo Okugawa, Shoji Ishibashi, Shuichi Murakami, and Takashi Miyake, “Dirac point in Trigonal Tellurium and Selenium”, JPS Conf. Proc. 5, 011024 (2015).
日本語記事 (in Japanese)
レビュー記事
固体物理 60巻, 11号 (2025) 「準結晶におけるトポロジカル超伝導 -ギャップレスなトポロジカル相への実空間アプローチ-」、奥川亮
固体物理 52巻 11号 (2017) 「第一原理計算に基づくトポロジカル半金属の新物質・新物性」、平山元昭、奥川亮、村上修一