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Ieda, Junichi
Hoshasen To Sangyo, (146), p.48 - 52, 2019/06
no abstracts in English
atoms in Ni
Fe
N (
= 1 and 3) films revealed by X-ray absorption spectroscopy and magnetic circular dichroismTakata, 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
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：4 Percentile：43.58(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.
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：4 Percentile：40.38(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：7 Percentile：53.77(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
Percentile：100(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
Abe, Hiroshi; Maekawa, Masaki; Zhou, K.*; Kawasuso, Atsuo
no journal, ,
no abstracts in English
Kawasuso, Atsuo
no journal, ,
no abstracts in English
Kawasuso, Atsuo
no journal, ,
no abstracts in English
Ieda, Junichi; Maekawa, Sadamichi
no journal, ,
We study magnetic anisotropy in antiferromagnets (AFMs) with the inversion symmetry breaking (ISB). Magnetic anisotropy determines an energy barrier that separates preferable orientations of staggered magnetization in AFMs, and in its sense, understanding and controlling the magnetic anisotropy energy (MAE) in AFMs are fundamentally important for devising magnetic memory bits that should be reliably robust against any external (thermal, magnetic field, and electric current) noises. It has also been pointed out that a large value of MAE in AFMs is advantageous for the exchange bias field that is routinely used to fix magnetization direction at the AFM/FM interface in current magnetic memory technology. In this work, we employ two representative models for the AFMs and obtain the MAE as a consequence of the cooperation of the Rashba spin-orbit (RSO) and exchange interactions. For the global ISB model the MAE shows a transition depending on the magnitude of the RSO coupling: the easy-plane magnetic anisotropy is favored with the small RSO coupling whereas the perpendicular magnetic anisotropy (PMA) is induced with the large RSO coupling. For the local ISB the PMA is generally results in, which contrasts to the corresponding ferromagnetic case in which the condition for the PMA depends on the band structure and dimensionality. These features are particularly important for stabilizing the direction of the order parameter in AMF nanostructures and for electrical-field control of the MAE via the externally modulated RSO coupling.
Ieda, Junichi; Maekawa, Sadamichi
no journal, ,
Recently spintronics phenomenon based on antiferromagnets has drawn much attention. In 2014, we proposed a mechanism that the Rashba spin-orbital interaction produces magnetic anisotropy due to competition with magnetic exchange interaction in a ferromagnetic thin film. This time the theory is extended to antiferromagnet with the Rashba spin-orbital interaction. Conduction electron spin that hops between the nearest neighbor sites on a lattice with antiferromagnetic order in two sublattice is considered. Two kinds of lattice models which feel an on-site exchange interaction and the Rashba interaction of (a) the same sign for the nearest neighbor hopping, or (b) the different sign for the next nearest neighbor hopping are investigated. Former is a model of the Rashba effect occurring at the interface between the antiferromagnetic thin film and another substance and the latter is for the Rashba effect in the antiferromagnet in which the inversion symmetry locally broken, such as CuMnAs. For each model, the angle dependence of the total energy on the antiferromagnetic order-parameter direction is obtained and the expression of the uniaxial magnetic anisotropy constant is derived. In model (a), it is shown that transition from easy plane anisotropy to perpendicular magnetic anisotropy occurs with increasing Rashba interaction. On the other hand, in model (b), it is shown that Rashba interaction always favors the perpendicular magnetic anisotropy as a result of competition with exchange interaction.
Takeda, Masayasu
no journal, ,
no abstracts in English
Fe
OShamoto, Shinichi; Ito, Takashi; Onishi, Hiroaki; Matsuura, Masato*; Akatsu, Mitsuhiro*; Nakamura, Mitsutaka; Inamura, Yasuhiro; Kodama, Katsuaki; Kawamura, Seiko; Nemoto, Yuichi*; et al.
no journal, ,
no abstracts in English
Ieda, Junichi; Yamane, Yuta*; Sinova, J.*
no journal, ,
