Kei Takahashi

J-GLOBAL         Last updated: Feb 5, 2019 at 10:38
 
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Name
Kei Takahashi
E-mail
kei.takahashiriken.jp
URL
https://www.cems.riken.jp/jp/laboratory/scirg
Affiliation
RIKEN Center for Emergent Matter Science
Job title
Senior Research Scientist
Degree
Dr.(Engineering)
Research funding number
90469932

Research Areas

 
 

Academic & Professional Experience

 
Apr 2013
 - 
Today
Senior Research Scientist, Strong Correlation Interface Research Group, RIKEN Center for Emergent Matter Science
 

Education

 
Apr 1999
 - 
Mar 2002
Doctor course, Faculty of engineering, University of Tokyo
 

Awards & Honors

 
May 2015
Nature Physics Poster Prize, Nature publishing group
 
Oct 2014
IWOE-21 Best Speaker Award
 

Published Papers

 
Yoshimi R., Yasuda K., Tsukazaki A., Takahashi K. S., Kawasaki M., Tokura Y.
SCIENCE ADVANCES   4(12)    Dec 2018   [Refereed]
Watanabe R., Yoshimi R., Shirai M., Tanigaki T., Kawamura M., Tsukazaki A., Takahashi K. S., Arita R., Kawasaki M., Tokura Y.
APPLIED PHYSICS LETTERS   113(18)    Oct 2018   [Refereed]
Kawamura Minoru, Mogi Masataka, Yoshimi Ryutaro, Tsukazaki Atsushi, Kozuka Yusuke, Takahashi Kei S., Kawasaki Masashi, Tokura Yoshinori
PHYSICAL REVIEW B   98(14)    Oct 2018   [Refereed]
Mogi M., Tsukazaki A., Kaneko Y., Yoshimi R., Takahashi K. S., Kawasaki M., Tokura Y.
APL MATERIALS   6(9)    Sep 2018   [Refereed]
Takahashi Kei S., Ishizuka Hiroaki, Murata Tomoki, Wang Qing Y., Tokura Yoshinori, Nagaosa Naoto, Kawasaki Masashi
SCIENCE ADVANCES   4(7)    Jul 2018   [Refereed]
Yasuda K., Mogi M., Yoshimi R., Tsukazaki A., Takahashi K. S., Kawasaki M., Kagawa F., Tokura Y.
SCIENCE   358(6368) 1311-1314   Dec 2017   [Refereed]
K. S. Takahashi, K. S. Takahashi, Y. Matsubara, Y. Matsubara, M. S. Bahramy, M. S. Bahramy, N. Ogawa, D. Hashizume, Y. Tokura, Y. Tokura, M. Kawasaki, M. Kawasaki
Scientific Reports   7    Dec 2017
© The Author(s) 2017. Ferroelectric polarization and metallic conduction are two seemingly irreconcilable properties that cannot normally coexist in a single system, as the latter tends to screen the former. Polar metals, however, defy this rule a...
M. Uchida, M. Ide, H. Watanabe, K. S. Takahashi, K. S. Takahashi, Y. Tokura, Y. Tokura, M. Kawasaki, M. Kawasaki
APL Materials   5    Oct 2017
© 2017 Author(s). We report the growth of superconducting Sr 2 RuO 4 films by oxide molecular beam epitaxy (MBE). Careful tuning of the Ru flux with an electron beam evaporator enables us to optimize growth conditions including the Ru/Sr flux rati...
K. Yasuda, A. Tsukazaki, R. Yoshimi, K. Kondou, K. S. Takahashi, K. S. Takahashi, Y. Otani, Y. Otani, M. Kawasaki, M. Kawasaki, Y. Tokura, Y. Tokura
Physical Review Letters   119    Sep 2017
© 2017 American Physical Society. The current-nonlinear Hall effect or second harmonic Hall voltage is widely used as one of the methods for estimating charge-spin conversion efficiency, which is attributed to the magnetization oscillation by spin...
Minoru Kawamura, Ryutaro Yoshimi, Atsushi Tsukazaki, Kei S. Takahashi, Kei S. Takahashi, Masashi Kawasaki, Masashi Kawasaki, Yoshinori Tokura, Yoshinori Tokura
Physical Review Letters   119    Jul 2017
© 2017 American Physical Society. The instability of the quantum anomalous Hall (QAH) effect has been studied as a function of the electric current and temperature in ferromagnetic topological insulator thin films. We find that a characteristic cu...
M. Mogi, M. Kawamura, R. Yoshimi, A. Tsukazaki, Y. Kozuka, N. Shirakawa, K. S. Takahashi, K. S. Takahashi, M. Kawasaki, M. Kawasaki, Y. Tokura, Y. Tokura
Nature Materials   16 516-521   May 2017
© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. The axion insulator which may exhibit an exotic quantized magnetoelectric effect is one of the most interesting quantum phases predicted for the three-dimensional t...
Masataka Mogi, Minoru Kawamura, Atsushi Tsukazaki, Ryutaro Yoshimi, Kei S. Takahashi, Kei S. Takahashi, Masashi Kawasaki, Masashi Kawasaki, Yoshinori Tokura, Yoshinori Tokura
Science Advances   3    Jan 2017
Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. Exploration of novel electromagnetic phenomena is a subject of great interest in topological quantum materials. One of the ...
K. Kondou, R. Yoshimi, A. Tsukazaki, Y. Fukuma, Y. Fukuma, J. Matsuno, K. S. Takahashi, M. Kawasaki, M. Kawasaki, Y. Tokura, Y. Tokura, Y. Otani, Y. Otani
Nature Physics   12 1027-1031   Nov 2016
© 2016 Macmillan Publishers Limited. All rights reserved. Spin-momentum locking in the Dirac surface state of a topological insulator (TI) offers a distinct possibility for highly efficient charge-to-spin current (C-S) conversion compared with spi...
K. Yasuda, A. Tsukazaki, R. Yoshimi, K. S. Takahashi, M. Kawasaki, M. Kawasaki, Y. Tokura, Y. Tokura
Physical Review Letters   117    Sep 2016
© 2016 American Physical Society. We report current-direction dependent or unidirectional magnetoresistance (UMR) in magnetic or nonmagnetic topological insulator (TI) heterostructures, Crx(Bi1-ySby)2-xTe3/(Bi1-ySby)2Te3, that is several orders of...
Okada KN, Takahashi Y, Mogi M, Yoshimi R, Tsukazaki A, Takahashi KS, Ogawa N, Kawasaki M, Tokura Y
Nature communications   7 12245   Jul 2016   [Refereed]
Shinichi Itoh, Shinichi Itoh, Yasuo Endoh, Yasuo Endoh, Tetsuya Yokoo, Tetsuya Yokoo, Soshi Ibuka, Je Geun Park, Je Geun Park, Yoshio Kaneko, Kei S. Takahashi, Yoshinori Tokura, Yoshinori Tokura, Naoto Nagaosa, Naoto Nagaosa
Nature Communications   7    Jun 2016
Weyl fermions that emerge at band crossings in momentum space caused by the spin-orbit interaction act as magnetic monopoles of the Berry curvature and contribute to a variety of novel transport phenomena such as anomalous Hall effect and magnetor...
Matsubara Y, Takahashi KS, Bahramy MS, Kozuka Y, Maryenko D, Falson J, Tsukazaki A, Tokura Y, Kawasaki M
Nature communications   7 11631   May 2016   [Refereed]
K. Yasuda, R. Wakatsuki, T. Morimoto, R. Yoshimi, A. Tsukazaki, K. S. Takahashi, M. Ezawa, M. Kawasaki, N. Nagaosa, Y. Tokura
Nature Physics      Feb 2016
© 2016 Nature Publishing Group Geometry, both in momentum and in real space, plays an important role in the electronic dynamics of condensed matter systems. Among them, the Berry phase associated with nontrivial geometry can be an origin of the tr...
Yoshimi R, Yasuda K, Tsukazaki A, Takahashi KS, Nagaosa N, Kawasaki M, Tokura Y
Nature communications   6 8530   Oct 2015   [Refereed]
M. Mogi, R. Yoshimi, A. Tsukazaki, A. Tsukazaki, K. Yasuda, Y. Kozuka, K. S. Takahashi, M. Kawasaki, M. Kawasaki, Y. Tokura, Y. Tokura
Applied Physics Letters   107 -keitakahashi26   Nov 2015   [Refereed]
© 2015 AIP Publishing LLC. Quantum anomalous Hall effect (QAHE), which generates dissipation-less edge current without external magnetic field, is observed in magnetic-ion doped topological insulators (TIs) such as Cr- and V-doped (Bi,Sb)2Te3. The...

Conference Activities & Talks

 
Quantum Hall effect in delta-doped SrTiO3 by high temperature gas source MBE growth [Invited]
Kei Takahashi
European-MRS fall meeting 2015   15 Sep 2015   
Growth and physical properties of 4d and 5d transition metal oxide films [Invited]
Kei Takahashi
International Conference on Superconductivity and Magnetism   29 Apr 2012   
Control of physical properties of low carrier density superconductor by local field effect [Invited]
Kei Takahashi
International Workshop on Superconductivity in Diamond and Related Materials 2008   7 Jul 2008   

Research Grants & Projects

 
Ministry of Education, Culture, Sports, Science and Technology: Grants-in-Aid for Scientific Research(若手研究(B))
Project Year: 2009 - 2010    Investigator(s): Kei TAKAHASHI
In order to control the charge and orbital ordered pattern by epitaxial strain, Nd_<0.25>Sr_<1.75>MnO_4 thin films were fabricated on the (100) surface of LaSrGaO_4 and LaSrAlO_4 substrates. Due to the anisotropic strain in the MnO_2 plane, the or...