K
Koichiro Yaji
Researcher at University of Tokyo
Publications - 106
Citations - 3398
Koichiro Yaji is an academic researcher from University of Tokyo. The author has contributed to research in topics: Topological insulator & Angle-resolved photoemission spectroscopy. The author has an hindex of 20, co-authored 99 publications receiving 2434 citations. Previous affiliations of Koichiro Yaji include Kyoto University & Hiroshima University.
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Journal ArticleDOI
Valley-dependent spin polarization in bulk MoS2 with broken inversion symmetry
Ryuji Suzuki,M. Sakano,Yijin Zhang,Ryosuke Akashi,Daisuke Morikawa,Ayumi Harasawa,Koichiro Yaji,Kenta Kuroda,Koji Miyamoto,Taichi Okuda,Kyoko Ishizaka,Ryotaro Arita,Yoshihiro Iwasa +12 more
TL;DR: The direct observation of valley-dependent out-of-plane spin polarization in an archetypal transition-metal dichalcogenide--MoS2--using spin- and angle-resolved photoemission spectroscopy is reported, in fair agreement with a first-principles theoretical prediction.
Journal ArticleDOI
Observation of topological superconductivity on the surface of an iron-based superconductor
Peng Zhang,Koichiro Yaji,Takahiro Hashimoto,Yuichi Ota,Takeshi Kondo,Kozo Okazaki,Zhijun Wang,Jinsheng Wen,Genda Gu,Hong Ding,Shik Shin +10 more
TL;DR: The researchers found that the surface of the iron superconductor FeTe0.55Se0.45 satisfies the required conditions for topological superconductivity, providing a simple and possibly high-temperature platform for realizing Majorana states.
Journal Article
Observation of topological superconductivity on the surface of iron-based superconductor
Peng Zhang,Koichiro Yaji,Takahiro Hashimoto,Yuichi Ota,Takeshi Kondo,Kozo Okazaki,Zhijun Wang,Jinsheng Wen,Genda Gu,Hong Ding,Shik Shin +10 more
TL;DR: In this paper, the surface of the iron-based superconductor FeTe0.55Se0.45 has been shown to be topologically superconducting, providing a simple and possibly high-temperature platform for realizing Majorana states.
Journal ArticleDOI
Large Rashba spin splitting of a metallic surface-state band on a semiconductor surface.
Koichiro Yaji,Yoshiyuki Ohtsubo,Shinichiro Hatta,Hiroshi Okuyama,Koji Miyamoto,Taichi Okuda,Akio Kimura,Hirofumi Namatame,Masaki Taniguchi,Masaki Taniguchi,Tetsuya Aruga +10 more
TL;DR: It is demonstrated that a metallic surface-state band with a dominant Pb 6p character exhibits a large Rashba spin splitting of 200 meV and an effective mass of 0.028 me at the Fermi level, which provides a material basis for the novel field of spin transport/accumulation on semiconductor surfaces.
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Multiple topological states in iron-based superconductors
Peng Zhang,Zhijun Wang,Xianxin Wu,Koichiro Yaji,Yukiaki Ishida,Yoshimitsu Kohama,Guangyang Dai,Yue Sun,Cédric Bareille,Kenta Kuroda,Takeshi Kondo,Kozo Okazaki,Koichi Kindo,Xiancheng Wang,Changqing Jin,Jiangping Hu,Ronny Thomale,Kazuki Sumida,Shilong Wu,Koji Miyamoto,Taichi Okuda,Hong Ding,Genda Gu,Tsuyoshi Tamegai,Takuto Kawakami,Masatoshi Sato,Shik Shin +26 more
TL;DR: In this paper, the authors identify both topological insulator and Dirac semimetal states near the Fermi energy in different iron-based high-temperature superconducting compounds.