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Ieda, Junichi
FBNews, (528), p.1 - 5, 2020/12
no abstracts in English
Nakata, Koki; Takayoshi, Shintaro*
Physical Review B, 102(9), p.094417_1 - 094417_11, 2020/09
Times Cited Count:0 Percentile:100(Materials Science, Multidisciplinary)Combining the technologies of quantum optics and magnonics [A. Rebei and J. Hohlfeld, Phys. Lett. A 372, 1915 (2008); J. Appl. Phys. 103, 07B118 (2008)] [S. Takayoshi et al., Phys. Rev. B 90, 214413 (2014); S. Takayoshi et al., Phys. Rev. B 90, 085150 (2014)], we find that the circularly polarized laser can dynamically realize the quasiequilibrium magnon Bose-Einstein condensates in insulating ferrimagnets. This provides an access to coherent magnons in the high frequency regime of the order of terahertz.
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:0 Percentile:100(Multidisciplinary Sciences)Ito, Keita*; Yasutomi, Yoko*; Zhu, S.*; Nurmamat, M.*; Tahara, Masaki*; Toko, Kaoru*; Akiyama, Ryota*; Takeda, Yukiharu; Saito, Yuji; Oguchi, Tamio*; et al.
Physical Review B, 101(10), p.104401_1 - 104401_8, 2020/03
Times Cited Count:1 Percentile:31.73(Materials Science, Multidisciplinary)Nakata, Koki; Onuma, Yuichi*; Matsuo, Mamoru*
Physical Review B, 100(1), p.014406_1 - 014406_8, 2019/07
Times Cited Count:0 Percentile:100(Materials Science, Multidisciplinary)Extending a Boltzmann-Langevin theory to magnons, we show a universality of current-noise suppression in diffusive systems against the difference of quantum-statistical properties of bosons and fermions.
Nakata, Koki; Kim, S. K.*; Takayoshi, Shintaro*
Physical Review B, 100(1), p.014421_1 - 014421_9, 2019/07
Times Cited Count:2 Percentile:56.85(Materials Science, Multidisciplinary)We study the laser control of magnon topological phases induced by the Aharonov-Casher effect in insulating antiferromagnets (AFs). Using Floquet formalism, we study nonequilibrium magnon dynamics away from the adiabatic limit and its effect on topological phenomena. Our results provide a handle to control and design magnon topological properties in the insulating AF, and thus open a new door to "photonic magnonics".
Ieda, Junichi
Hoshasen To Sangyo, (146), p.48 - 52, 2019/06
no abstracts in English
Kim, S. K.*; Nakata, Koki; Loss, D.*; Tserkovnyak, Y.*
Physical Review Letters, 122(5), p.057204_1 - 057204_6, 2019/02
Times Cited Count:12 Percentile:8.44(Physics, Multidisciplinary)We theoretically study the thermal Hall effect by magnons in skyrmion crystal phases of ferrimagnets in the vicinity of the angular momentum compensation point (CP). For an experimental proposal, we predict that themagnonic thermal Hall conductivity changes its sign when the ferrimagnet is tuned across the CP, providing a way to control heat flux in spin-caloritronic devices on the one hand and a feasible way todetect the CP of ferrimagnets on the other hand.
Takata, Fumiya*; Ito, Keita*; Takeda, Yukiharu; Saito, Yuji; Takanashi, Koki*; Kimura, Akio*; Suemasu, Takashi*
Physical Review Materials (Internet), 2(2), p.024407_1 - 024407_5, 2018/02
Times Cited Count:7 Percentile:43.2(Materials Science, Multidisciplinary)Hou, D.*; Qiu, Z.*; Barker, J.*; Sato, Koji*; Yamamoto, Kei; Vlez, S.*; Gomez-Perez, J. M.*; Hueso, L. E.*; Casanova, F.*; Saito, Eiji
Physical Review Letters, 118(14), p.147202_1 - 147202_6, 2017/04
Times Cited Count:71 Percentile:1.63(Physics, Multidisciplinary)Seo, 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:28.22(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 YFe
O
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.
Matsuo, Mamoru; Saito, Eiji; Maekawa, Sadamichi
Journal of the Physical Society of Japan, 86(1), p.011011_1 - 011011_7, 2017/01
Times Cited Count:11 Percentile:24.69(Physics, Multidisciplinary)We investigate the interconversion phenomena between spin and mechanical angular momentum in moving objects. In particular, the recent results on spin manipulation and spin-current generation by mechanical motion are examined. In accelerating systems, spin-dependent gauge fields emerge, which enable the conversion from mechanical angular momentum into spins. Such a spin-mechanical effect is predicted by quantum theory in a non-inertial frame. Experiments which confirm the effect, i.e., the resonance frequency shift in nuclear magnetic resonance, the stray field measurement of rotating metals, and electric voltage generation in liquid metals, are discussed.
Matsuo, Mamoru
Oyo Butsuri, 86(1), p.31 - 35, 2017/01
Spin-current generation by fluid motion is investigated. Spin-rotation coupling emerges in a rotating object and allows the angular momentum conversion from mechanical angular momentum into spins. We predicted that the spin current is mechanically generated along the vorticity gradient of the liquid metal pipe flow. Such spin-mechanical effect is experimentally confirmed by electric voltage generation in liquid metals. The use of the interconversion between spin and mechanical angular momentum opens up a new field of spintronics, where spin and mechanical motion are harmonized.
Kawasuso, Atsuo
Yodenshi Kagaku, (4), p.9 - 22, 2015/02
In this article, I report, the spin polarization of positrons emitted from radioisotopes, the development of spin-polarized beams, the fundamental aspects of spin-polarized positron annihilation method, and, the investigation of current-induced spin polarization on metal surfaces through the spin-polarized positronium annihilation.
Kuzubov, A. A.*; Kovaleva, E. A.*; Avramov, P. V.*; Kuklin, A. V.*; Mikhaleva, N. S.*; Tomilin, F. N.*; Sakai, Seiji; Entani, Shiro; Matsumoto, Yoshihiro*; Naramoto, Hiroshi*
Journal of Applied Physics, 116(8), p.084309_1 - 084309_4, 2014/08
Times Cited Count:8 Percentile:56.45(Physics, Applied)Avramov, P. V.*; Kuzubov, A. A.*; Sakai, Seiji; Otomo, Manabu*; Entani, Shiro; Matsumoto, Yoshihiro*; Eleseeva, N. S.*; Pomogaev, V. A.*; Naramoto, Hiroshi*
Journal of Porphyrins and Phthalocyanines, 18(7), p.552 - 568, 2014/07
Times Cited Count:1 Percentile:93.19(Chemistry, Multidisciplinary)Sakai, Seiji; Matsumoto, Yoshihiro*; Entani, Shiro; Naramoto, Hiroshi*; Koide, Akihiro*; Fujikawa, Takashi*; Yamauchi, Yasushi*; Amemiya, Kenta*
no journal, ,
no abstracts in English
Zhang, H.; Yamamoto, Shunya; Li, H.; Maekawa, Masaki; Fukaya, Yuki; Kawasuso, Atsuo; Seki, Takeshi*; Saito, Eiji*; Takanashi, Koki*
no journal, ,
Matsumoto, Yoshihiro*; Entani, Shiro; Koide, Akihiro*; Otomo, Manabu*; Avramov, P.*; Naramoto, Hiroshi*; Amemiya, Kenta*; Fujikawa, Takashi*; Sakai, Seiji
no journal, ,
no abstracts in English
Takeda, Masayasu
no journal, ,
no abstracts in English