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Takahashi, Ryo*; Chudo, Hiroyuki; Matsuo, Mamoru; Harii, Kazuya*; Onuma, Yuichi*; Maekawa, Sadamichi; Saito, Eiji
Nature Communications (Internet), 11, p.3009_1 - 3009_6, 2020/06
Times Cited Count：18 Percentile：79.38(Multidisciplinary Sciences)Kondo, Yasuhiro; Hirano, Koichiro; Ito, Takashi; Kikuzawa, Nobuhiro; Kitamura, Ryo; Morishita, Takatoshi; Oguri, Hidetomo; Okoshi, Kiyonori; Shinozaki, Shinichi; Shinto, Katsuhiro; et al.
Journal of Physics; Conference Series, 1350, p.012077_1 - 012077_7, 2019/12
Times Cited Count：1 Percentile：51.97(Physics, Particles & Fields)We have upgraded a 3-MeV linac at J-PARC. The ion source is same as the J-PARC linac's, and the old 30-mA RFQ is replaced by a spare 50-mA RFQ, therefore, the beam energy is 3 MeV and the nominal beam current is 50 mA. The main purpose of this system is to test the spare RFQ, but also used for testing of various components required in order to keep the stable operation of the J-PARC accelerator. The accelerator has been already commissioned, and measurement programs have been started. In this paper, present status of this 3-MeV linac is presented.
Fe
O
cantileversSeo, Y.-J.*; Harii, Kazuya; Takahashi, Ryo*; Chudo, Hiroyuki; Oyanagi, Koichi*; Qiu, Z.*; Ono, Takahito*; Shiomi, Yuki*; Saito, Eiji
Applied Physics Letters, 110(13), p.132409_1 - 132409_4, 2017/03
Times Cited Count：12 Percentile：50.54(Physics, Applied)We have fabricated ferrite cantilevers in which their vibrational properties can be controlled by external magnetic fields. Submicron-scale cantilever structures were made from YFeO films by physical etching combined with the use of a focused ion beam milling technique. We found that the cantilevers exhibit two resonance modes which correspond to horizontal and vertical vibrations. Under external magnetic fields, the resonance frequency of the horizontal mode increases, while that of the vertical mode decreases, quantitatively consistent with our numerical simulation for magnetic forces. The changes in resonance frequencies with magnetic fields reach a few percent, showing that an efficient magnetic control of resonance frequencies was achieved.
Takahashi, Ryo*; Matsuo, Mamoru; Ono, Masao; Harii, Kazuya; Chudo, Hiroyuki; Okayasu, Satoru; Ieda, Junichi; Takahashi, Saburo*; Maekawa, Sadamichi; Saito, Eiji
Nature Physics, 12, p.52 - 56, 2016/01
Times Cited Count：109 Percentile：96.35(Physics, Multidisciplinary)Ono, Masao; Chudo, Hiroyuki; Harii, Kazuya; Okayasu, Satoru; Matsuo, Mamoru; Ieda, Junichi; Takahashi, Ryo*; Maekawa, Sadamichi; Saito, Eiji
Physical Review B, 92(17), p.174424_1 - 174424_4, 2015/11
Times Cited Count：30 Percentile：74.42(Materials Science, Multidisciplinary)Qiu, Z.*; Ando, Kazuya*; Uchida, Kenichi*; Kajiwara, Yosuke*; Takahashi, Ryo*; Nakayama, Hiroyasu*; An, Toshu*; Fujikawa, Yasunori*; Saito, Eiji
Applied Physics Letters, 103(9), p.092404_1 - 092404_4, 2013/08
Times Cited Count：116 Percentile：95.79(Physics, Applied)A platinum (Pt)/yttrium iron garnet (YIG) bilayer system with a well-controlled interface has been developed; spin mixing conductance at the Pt/YIG interface has been studied. A clear interface with good crystal perfection is experimentally demonstrated to be one of the important factors for an ultimate spin mixing conductance. The spin mixing conductance is obtained to be 1.3
10
m
at the well-controlled Pt/YIG interface, which is close to a theoretical prediction.
Fe
/Pt filmsNakayama, Hiroyasu*; Ando, Kazuya*; Harii, Kazuya; Yoshino, Tatsuro*; Takahashi, Ryo*; Kajiwara, Yosuke*; Uchida, Kenichi*; Fujikawa, Yasunori*; Saito, Eiji
Physical Review B, 85(14), p.144408_1 - 144408_7, 2012/04
Times Cited Count：192 Percentile：97.97(Materials Science, Multidisciplinary)Geometric effects on the inverse spin Hall effect (ISHE) induced by the spin pumping driven by the ferromagnetic resonance (FMR) have been investigated quantitatively. We measured the FMR spectra and the electromotive force induced by the ISHE with changing the size and the thickness in NiFe/Pt films. The intensity of generated charge currents due to the ISHE changes systematically with changing the film geometry. The experimental results show a clear difference between NiFe and Pt thickness dependence of the ISHE induced by the spin pumping.
Matsuo, Mamoru; Ieda, Junichi; Takahashi, Ryo*; Harii, Kazuya; Saito, Eiji; Maekawa, Sadamichi
no journal, ,
We theoretically investigate the mechanical generation of spin current. We show that mechanical angular momentum carried by macroscopic body can be converted into spin angular momentum via spin-rotation coupling.
Matoba, Shiro; Narumi, Kazumasa; Saito, Yuichi; Yamada, Keisuke; Chiba, Atsuya; Koizumi, Tetsuo*; Takahashi, Karin*; Ishikawa, Manabu*; Shiromaru, Haruo*; Kato, Ryoya*; et al.
no journal, ,
no abstracts in English
Harii, Kazuya; Matsuo, Mamoru; Takahashi, Ryo; Ono, Masao; Ieda, Junichi; Chudo, Hiroyuki; Okayasu, Satoru; Maekawa, Sadamichi; Saito, Eiji
no journal, ,
Spin current, a flow of spins, is a key concept in the field of spintronics. It is generated by using angular momentum conversion between magnetization, photon, electric current and so on. On the other hand, mechanical angular momentum due to mechanical motion has not been utilized for spin-current generation so far. In this talk, we discuss theoretical and experimental results for spin-current generation from mechanical motion. The spin-current generation by mechanical motion stems from the spin-rotation coupling, which is the fundamental interaction between spin angular momentum and rotational motion.
Takahashi, Ryo; Maekawa, Sadamichi; Saito, Eiji
no journal, ,
Takahashi, Ryo; Harii, Kazuya*; Matsuo, Mamoru; Maekawa, Sadamichi; Saito, Eiji
no journal, ,
Chudo, Hiroyuki; Imai, Masaki; Harii, Kazuya; Ono, Masao; Takahashi, Ryo*; Matsuo, Mamoru; Maekawa, Sadamichi; Saito, Eiji
no journal, ,
no abstracts in English
