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Nakata, Koki
Kotai Butsuri, 56(8), p.429 - 439, 2021/08
We review the thermomagnetic relation of bosons, the Wiedemann-Franz law for magnon transport, and discuss the universality.
Nakata, Koki; Takayoshi, Shintaro*
Physical Review B, 102(9), p.094417_1 - 094417_11, 2020/09
Times Cited Count:8 Percentile:54.31(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.
Yamasaki, Atsushi*; Fujiwara, Hidenori*; Tachibana, Shoichi*; Iwasaki, Daisuke*; Higashino, Yuji*; Yoshimi, Chiaki*; Nakagawa, Koya*; Nakatani, Yasuhiro*; Yamagami, Kohei*; Aratani, Hidekazu*; et al.
Physical Review B, 94(11), p.115103_1 - 115103_10, 2016/11
Times Cited Count:17 Percentile:61.47(Materials Science, Multidisciplinary)In this study, we systematically investigate three-dimensional(3D) momentum-resolved electronic structures of Ruddlesden-Popper-type iridium oxides SrIrO using soft-X-ray angle-resolved photoemission spectroscopy (SX-ARPES). Our results provide direct evidence of an insulator-to-metal transition that occurs upon increasing the dimensionality of the IrO-plane structure. This transition occurs when the spin-orbit-coupled = 1/2 band changes its behavior in the dispersion relation and moves across the Fermi energy. By scanning the photon energy over 350 eV, we reveal the 3D Fermi surface in SrIrO and -dependent oscillations of photoelectron intensity in SrIrO. To corroborate the physics deduced using low-energy ARPES studies, we propose to utilize SX-ARPES as a powerful complementary technique, as this method surveys more than one whole Brillouin zone and provides a panoramic view of electronic structures.
Kitatani, Fumito
Kaku Deta Nyusu (Internet), (114), p.44 - 49, 2016/06
no abstracts in English
Kitatani, Fumito; Harada, Hideo; Goko, Shinji*; Iwamoto, Nobuyuki; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*; Igashira, Masayuki*
Journal of Nuclear Science and Technology, 53(4), p.475 - 485, 2016/04
Times Cited Count:2 Percentile:43.6(Nuclear Science & Technology)Kitatani, Fumito; Harada, Hideo; Goko, Shinji*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*
JAEA-Conf 2014-002, p.57 - 62, 2015/02
Kondo, Takeo*; Utsunomiya, Hiroaki*; Goriely, S.*; Iwamoto, Chihiro*; Akimune, Hidetoshi*; Yamagata, Tamio*; Toyokawa, Hiroyuki*; Harada, Hideo; Kitatani, Fumito; Lui, Y.-W.*; et al.
Nuclear Data Sheets, 119, p.310 - 313, 2014/05
Times Cited Count:2 Percentile:19.31(Physics, Nuclear)Utsunomiya, Hiroaki*; Goriely, S.*; Kondo, Takeo*; Iwamoto, Chihiro*; Akimune, Hidetoshi*; Yamagata, Tamio*; Toyokawa, Hiroyuki*; Harada, Hideo; Kitatani, Fumito; Lui, Y.-W.*; et al.
Physical Review C, 88(1), p.015805_1 - 015805_6, 2013/07
Times Cited Count:72 Percentile:96.67(Physics, Nuclear)Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Yamagata, Tamio*; Iwamoto, Chihiro*; Goriely, S.*; Daoutidis, I.*; Toyokawa, Hiroyuki*; Harada, Hideo; Kitatani, Fumito; Iwamoto, Nobuyuki; et al.
Proceedings of 14th International Symposium on Capture -Ray Spectroscopy and Related Topics, p.505 - 514, 2013/05
Kondo, Takeo*; Utsunomiya, Hiroaki*; Goriely, S.*; Daoutidis, I.*; Iwamoto, Chihiro*; Akimune, Hidetoshi*; Okamoto, Akiyuki*; Yamagata, Tamio*; Kamata, Masaki*; Ito, Osamu*; et al.
Physical Review C, 86(1), p.014316_1 - 014316_7, 2012/07
Times Cited Count:38 Percentile:87(Physics, Nuclear)Using quasi-monochromatic laser-Compton scattering rays, total photoneutron cross sections were measured for Pb near neutron threshold with a high-efficiency 4 neutron detector. Partial 1 and 1 photoneutron cross sections along with total cross sections were determined for Pb at four energies near threshold by measuring anisotropies in photoneutron emission with linearly-polarized rays. The 1 strength dominates over the 1 strength in the neutron channel where 1 photoneutron cross sections show extra strength of the pygmy dipole resonance in Pb near the neutron threshold corresponding to 0.32-0.42% of the Thomas-Reiche-Kuhn sum rule. Several units of B(1) strength were observed in Pb just above neutron threshold, which correspond to an 1 cross section less than 10% of the total photoneutron cross section.
Kondo, Takeo*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Yamagata, Tamio*; Okamoto, Akiyuki*; Harada, Hideo; Kitatani, Fumito; Shima, Tatsushi*; Horikawa, Ken*; Miyamoto, Shuji*
Nuclear Instruments and Methods in Physics Research A, 659(1), p.462 - 466, 2011/12
Times Cited Count:27 Percentile:89.24(Instruments & Instrumentation)We measured pulse-height spectra of 16.7 MeV laser-Compton scattering photons with a 6"5" NaI(Tl) detector for blank and three lead materials of 75.8, 50.9, and 25.9% transmissions at the NewSUBARU facility to investigate how the original Poisson distribution of the pulsed photons is modified after passing through thick-target materials. We present a well-prescribed method of determining the number of incident photons within 3.5% accuracy based on the response of the NaI(Tl) detector to the pulsed photon beams.
Utsunomiya, Hiroaki*; Goriely, S.*; Kamata, Masaki*; Akimune, Hidetoshi*; Kondo, Takeo*; Ito, Osamu*; Iwamoto, Chihiro*; Yamagata, Tamio*; Toyokawa, Hiroyuki*; Lui, Y.-W.*; et al.
Physical Review C, 84(5), p.055805_1 - 055805_6, 2011/11
Times Cited Count:43 Percentile:89.88(Physics, Nuclear)Photoneutron cross sections were measured for Sn, Sn, Sn, Sn, and Sn near neutron threshold with quasi-monochromatic laser-Compton scattering -rays. A systematic analysis of the present photoneutron data and existing neutron-capture data is made using the -ray strength function on the basis of the HFB+QRPA model of E1 strength supplemented with a pygmy dipole resonance, which was deduced from a previous study on Sn and Sn. Radiative neutron capture cross sections for two radioactive nuclei, Sn and Sn, are deduced through the -ray strength function method.
Utsunomiya, Hiroaki*; Goriely, S.*; Akimune, Hidetoshi*; Yamagata, Tamio*; Kondo, Takeo*; Iwamoto, Chihiro*; Okamoto, Akiyuki*; Harada, Hideo; Kitatani, Fumito; Goko, Shinji*; et al.
AIP Conference Proceedings 1377, p.255 - 259, 2011/10
Times Cited Count:0 Percentile:0.05Ito, Osamu*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Yamagata, Tamio*; Kondo, Takeo*; Kamata, Masaki*; Toyokawa, Hiroyuki*; Harada, Hideo; Kitatani, Fumito; Goko, Shinji*; et al.
AIP Conference Proceedings 1377, p.362 - 364, 2011/10
Times Cited Count:0 Percentile:0.05Utsunomiya, Hiroaki*; Goriely, S.*; Arteaga, D. P.*; Daoutidis, I.*; Akimune, Hidetoshi*; Yamagata, Tamio*; Kondo, Takeo*; Iwamoto, Chihiro*; Kamata, Masaki*; Ito, Osamu*; et al.
AIP Conference Proceedings 1377, p.450 - 452, 2011/10
Times Cited Count:0 Percentile:0.05Ito, Osamu*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Kondo, Takeo*; Kamata, Masaki*; Yamagata, Tamio*; Toyokawa, Hiroyuki*; Harada, Hideo; Kitatani, Fumito; Goko, Shinji*; et al.
Journal of Nuclear Science and Technology, 48(5), p.834 - 840, 2011/05
Times Cited Count:28 Percentile:89.79(Nuclear Science & Technology)Photoneutron cross section measurements were made for Au in the entire energy range of the (,n) channel based on a direct neutron-counting technique with quasi-monochromatic -rays produced in inverse Compton-scattering of laser photons with relativistic electrons. The data were analyzed with a least-squares method to deduce photoneutron cross sections. The analysis significantly reduced experimental uncertainties compared with those resulted from the photon difference method. The result is compared with the previous data by direct neutron-counting with -rays produced in positron annihilation in flight and by photoactivation with bremsstrahlung. The present data are in good agreement with the previous data near neutron threshold, while there remain some discrepancies between the present and the previous data above 10 MeV.
Utsunomiya, Hiroaki*; Goriely, S.*; Akimune, Hidetoshi*; Harada, Hideo; Kitatani, Fumito; Goko, Shinji*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*; Kondo, Takeo*; Ito, Osamu*; et al.
Physical Review C, 82(6), p.064610_1 - 064610_5, 2010/12
Times Cited Count:39 Percentile:88.79(Physics, Nuclear)The -ray strength function method (SF method) is devised to indirectly determine radiative neutron capture cross sections for radioactive nuclei. This method is applied here to the Pd case. Photoneutron cross sections were measured for Pd near neutron threshold with quasi-monochromatic laser-Compton-scattering -ray beams. These photoneutron cross sections as well as the reverse radiative neutron capture cross sections for Pd are used to provide constraints on the Pd(n,) Pd cross section.
Utsunomiya, Hiroaki*; Goriely, S.*; Akimune, Hidetoshi*; Yamagata, Tamio*; Kondo, Takeo*; Iwamoto, Chihiro*; Ito, Osamu*; Kamata, Masaki*; Io, Masanori*; Kususe, Koichi*; et al.
AIP Conference Proceedings 1377, p.447 - 449, 2010/10
Times Cited Count:0 Percentile:0.05Utsunomiya, Hiroaki*; Goriely, S.*; Akimune, Hidetoshi*; Harada, Hideo; Kitatani, Fumito; Goko, Shinji; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*; Kondo, Takeo*; Ito, Osamu*; et al.
Physical Review C, 81(3), p.035801_1 - 035801_5, 2010/03
Times Cited Count:37 Percentile:87.7(Physics, Nuclear)This manuscript presents photoneutron cross sections for Zr. Combining the present data with the previously published Zr data, we investigated the -ray strength function for zirconium isotopes systematically. We present a unified picture of the -ray strength function that consists of the HFB + QRPA model of E1 strength accompanied by an extra M1 strength attributable to giant M1 resonance. It is shown that the -ray strength function reproduces both (g,n) and (n,g) cross sections for Zr isotopes consistently.
Makinaga, Ayano*; Utsunomiya, Hiroaki*; Goriely, S.*; Kaihori, Takeshi*; Goko, Shinji*; Akimune, Hidetoshi*; Yamagata, Tamio*; Toyokawa, Hiroyuki*; Matsumoto, Tetsuro*; Harano, Hideki*; et al.
Physical Review C, 79(2), p.025801_1 - 025801_8, 2009/02
Times Cited Count:22 Percentile:79.7(Physics, Nuclear)Photoneutron cross sections were measured for Se immediately above the neutron separation energy with quasimonochromatic -ray beams to experimentally constrain the E1 strength function for Se. Two sets of the strength function and the level density that equally meet the experimental constraint predict largely different neutron capture cross sections for Se. Based on the Maxwell-averaged cross sections of the latest compilation complemented with the predicted cross sections for Se, we calculated N values of the main s-process component using a phenomenological model and deduced empirical abundances of the weak s-process component.