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Lyons, T. P.*; Puebla, J.*; Yamamoto, Kei; Deacon, R. S.*; Hwang, Y.*; Ishibashi, Koji*; Maekawa, Sadamichi*; Otani, Yoshichika*
Physical Review Letters, 131(19), p.196701_1 - 196701_6, 2023/11
Times Cited Count：0Liao, L.*; Puebla, J.*; Yamamoto, Kei; Kim, J.*; Maekawa, Sadamichi*; Hwang, Y.*; Ba, Y.*; Otani, Yoshichika*
Physical Review Letters, 131(17), p.176701_1 - 176701_6, 2023/10
Times Cited Count：0Chen, J.*; Yamamoto, Kei; Zhang, J.*; Ma, J.*; Wang, H.*; Sun, Y.*; Chen, M.*; Ma, J.*; Liu, S.*; Gao, P.*; et al.
Physical Review Applied (Internet), 19(2), p.024046_1 - 024046_9, 2023/02
Times Cited Count：4 Percentile：90.23(Physics, Applied)Lee, O.*; Yamamoto, Kei; Umeda, Maki; Zollitsch, C. W.*; Elyasi, M.*; Kikkawa, Takashi*; Saito, Eiji; Bauer, G. E. W.*; Kurebayashi, Hidekazu*
Physical Review Letters, 130(4), p.046703_1 - 046703_6, 2023/01
Times Cited Count：5 Percentile：80.44(Physics, Multidisciplinary)Yamamoto, Kei; Maekawa, Sadamichi*
Annalen der Physik, 11 Pages, 2023/00
Times Cited Count：0 Percentile：0(Physics, Multidisciplinary)Kyono, Atsushi*; Yamamoto, Genichiro*; Yoneda, Yasuhiro; Okada, Satoru*
Isotope News, (783), p.23 - 27, 2022/10
Mineral traps are attracting attention as an underground storage method for carbon dioxide. Carbon dioxide laden groundwater reacts with basalt to form magnesite. The formed magnesium carbonate phase varies in many ways, but we tried to clarify the structure because all of them pass through amorphous magnesium carbonate. Pair distribution function using high-energy X-ray diffraction revealed that amorphous magnesium carbonate has a structure similar to that of hydromagnesite. It can be said that it is a safe sequestration method as a carbon dioxide storage technology.
Yamamoto, Kei; Xu, M.*; Puebla, J.*; Otani, Yoshichika*; Maekawa, Sadamichi*
Journal of Magnetism and Magnetic Materials, 545, p.168672_1 - 168672_10, 2022/03
Times Cited Count：10 Percentile：52.49(Materials Science, Multidisciplinary)
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Sr
MnO heterostructuresZhang, J.*; Chen, M.*; Chen, J.*; Yamamoto, Kei; Wang, H.*; Hamdi, M.*; Sun, Y.*; Wagner, K.*; He, W.*; Zhang, Y.*; et al.
Nature Communications (Internet), 12, p.7258_1 - 7258_8, 2021/12
Times Cited Count：14 Percentile：77.64(Multidisciplinary Sciences)Yamamoto, Kei; Yu, W.*; Yu, T.*; Puebla, J.*; Xu, M.*; Maekawa, Sadamichi*; Bauer, G.*
Journal of the Physical Society of Japan, 89(11), p.113702_1 - 113702_5, 2020/11
Times Cited Count：10 Percentile：62.22(Physics, Multidisciplinary)Xu, M.*; Yamamoto, Kei; Puebla, J.*; Baumgaertl, K.*; Rana, B.*; Miura, Katsuya*; Takahashi, Hiromasa*; Grundler, D.*; Maekawa, Sadamichi*; Otani, Yoshichika*
Science Advances (Internet), 6(32), p.eabb1724_1 - eabb1724_4, 2020/08
Times Cited Count：81 Percentile：97.1(Multidisciplinary Sciences)Puebla, J.*; Xu, M.*; Rana, B.*; Yamamoto, Kei; Maekawa, Sadamichi*; Otani, Yoshichika*
Journal of Physics D; Applied Physics, 53(26), p.264002_1 - 264002_7, 2020/06
Times Cited Count：31 Percentile：87.05(Physics, Applied)Heussner, F.*; Talmelli, G.*; Geilen, M.*; Heinz, B.*; Br
cher, T.*; Meyer, T.*; Ciubotaru, F.*; Adelmann, C.*; Yamamoto, Kei; Serga, A. A.*; et al.
Physica Status Solidi; Rapid Research Letters, 14(4), p.1900695_1 - 1900695_6, 2020/04
Times Cited Count：31 Percentile：87.61(Materials Science, Multidisciplinary)Yamamoto, Kei
academist Journal (Internet), 3 Pages, 2019/09
no abstracts in English
Yamamoto, Kei; Thiang, G. C.*; Pirro, P.*; Kim, K.-W.*; Everschor-Sitte, K.*; Saito, Eiji*
Physical Review Letters, 122(21), p.217201_1 - 217201_5, 2019/05
Times Cited Count：24 Percentile：83.02(Physics, Multidisciplinary)Gomonay, O.*; Yamamoto, Kei; Sinova, J.*
Journal of Physics D; Applied Physics, 51(26), p.264004_1 - 264004_9, 2018/07
Times Cited Count：9 Percentile：42.42(Physics, Applied)Searching for novel spin caloric effects in antiferromagnets we study the properties of thermally activated magnons in the presence of an external spin current and temperature gradient. We predict the spin Peltier effect - generation of a heat flux by spin accumulation - in an antiferromagnetic insulator with cubic or uniaxial magnetic symmetry. This effect is related with spin-current induced splitting of the relaxation times of the magnons with opposite spin direction. We show that the Peltier effect can trigger antiferromagnetic domain wall motion with a force whose value grows with the temperature of a sample. We also demonstrate that the external spin current can induce the magnon spin Seebeck effect.
Yamamoto, Kei; Gomonay, O.*; Sinova, J.*; Schwiete, G.*
Physical Review B, 98(1), p.014406_1 - 014406_24, 2018/07
Times Cited Count：1 Percentile：5.02(Materials Science, Multidisciplinary)Qiu, Z.*; Hou, D.*; Barker, J.*; Yamamoto, Kei; Gomonay, O.*; Saito, Eiji*
Nature Materials, 17(7), p.577 - 580, 2018/05
Times Cited Count：98 Percentile：95.73(Chemistry, Physical)Colossal magnetoresistance (CMR) refers to a large change in electrical conductivity induced by a magnetic field in the vicinity of a metal-insulator transition. CMR occurs due to a correlation between the magnetic structure and electron conduction and has inspired extensive studies for decades. Here, in the antiferromagnetic insulator Cr
O, we found a sharp transition between conducting and nonconducting states for spin currents at room temperature. The spin-current transmission changes by two orders of magnitude within a narrow temperature window of 14K around the Neel temperature. The spin conductor-nonconductor transition can be modulated by a magnetic field, giving an isothermal change of spin-current transmission of up to 500%, effectively an on-off switch for spin currents.
Hou, D.*; Qiu, Z.*; Barker, J.*; Sato, Koji*; Yamamoto, Kei; V
lez, 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：109 Percentile：97.22(Physics, Multidisciplinary)Yamamoto, Masahiro*; Honda, Yosuke*; Miyajima, Tsukasa*; Uchiyama, Takashi*; Kobayashi, Masanori*; Muto, Toshiya*; Matsuba, Shunya*; Sakanaka, Shogo*; Sato, Kotaro*; Saito, Yoshio*; et al.
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.860 - 862, 2009/08
A newly 500 kV electron gun (2nd - 500 kV gun) for an ERL light source is designed at KEK. A new concept and state of-the-art technologies of vacuum system, ceramic insulators, high voltage power supply, photocathode and preparation system will be employed. The details are described in this report.
Yamamoto, Kei; Gomonay, O.*; Sinova, J.*; Schwiete, G.*
no journal, ,
We study a ferromagnetic-antiferromagnetic-normal metal tunneling junction using non-equilibrium Green's function techniques and derive microscopic formulae for various types of spin torque as well as charge and spin conductance. Relative strength of the torques and their dependence on control parameters such as the tunneling probabilities to the two leads are presented. We also discuss dynamical consequences of the different torques. Charge and spin transmission is shown to depend on the angle between the ferromagnetic and antiferromagnetic order parameters. We suggest potential applications of these angular dependences.
