R
Reiji Kumai
Researcher at KEK
Publications - 241
Citations - 11022
Reiji Kumai is an academic researcher from KEK. The author has contributed to research in topics: Ferroelectricity & Phase transition. The author has an hindex of 45, co-authored 225 publications receiving 9574 citations. Previous affiliations of Reiji Kumai include Graduate University for Advanced Studies & University of Yamanashi.
Papers
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Journal ArticleDOI
Inkjet printing of single-crystal films
Hiromi Minemawari,Toshikazu Yamada,Hiroyuki Matsui,Jun'ya Tsutsumi,Simon Haas,Ryosuke Chiba,Ryosuke Chiba,Reiji Kumai,Reiji Kumai,Tatsuo Hasegawa +9 more
TL;DR: It is shown that mixing fine droplets of an antisolvent and a solution of an active semiconducting component within a confined area on an amorphous substrate can trigger the controlled formation of exceptionally uniform single-crystal or polycrystalline thin films that grow at the liquid–air interfaces.
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Giant Rashba-type spin splitting in bulk BiTeI
Kyoko Ishizaka,Mohammad Saeed Bahramy,H. Murakawa,M. Sakano,Takahiro Shimojima,T. Sonobe,K. Koizumi,Shik Shin,Hirokazu Miyahara,Akio Kimura,Koji Miyamoto,Taichi Okuda,Hirofumi Namatame,Masaki Taniguchi,Masaki Taniguchi,Ryotaro Arita,Naoto Nagaosa,Kensuke Kobayashi,Youichi Murakami,Reiji Kumai,Reiji Kumai,Yoshio Kaneko,Yoshinori Onose,Yoshinori Tokura +23 more
TL;DR: The finding of a huge spin-orbit interaction effect in a polar semiconductor composed of heavy elements, BiTeI, where the bulk carriers are ruled by large Rashba-likespin splitting is described, confirming that the spin splitting is indeed derived from bulk atomic configurations.
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Above-room-temperature ferroelectricity in a single-component molecular crystal
Sachio Horiuchi,Yusuke Tokunaga,Gianluca Giovannetti,Silvia Picozzi,Hirotake Itoh,Ryo Shimano,Reiji Kumai,Yoshinori Tokura,Yoshinori Tokura +8 more
TL;DR: It is demonstrated that application of an electric field can coherently align the molecular polarities in crystalline croconic acid, as indicated by an increase of optical second harmonic generation, and produce a well-defined polarization hysteresis at room temperature.
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Ferroelectricity and polarity control in solid-state flip-flop supramolecular rotators.
Tomoyuki Akutagawa,Hiroyuki Koshinaka,Daisuke Sato,Sadamu Takeda,Shin Ichiro Noro,Hiroyuki Takahashi,Reiji Kumai,Yoshinori Tokura,Takayoshi Nakamura +8 more
TL;DR: It is shown that molecular rotator motion is controllable using an external electric field and demonstrated how such molecular rotators can be used as polarization rotation units in ferroelectric molecules.
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Magnetic and electronic properties of a single crystal of ordered double perovskite Sr 2 FeMoO 6
TL;DR: In this paper, a single crystal of ordered double perovskite oxide with a conducting ferromagnet has been prepared by the floating zone method, and the magnetic and electronic properties have been investigated.