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Zhu, M.*; Romerio, V.*; Steiger, N.*; Nabi, S. D.*; Murai, Naoki; Kawamura, Seiko; Povarov, K. Y.*; Skourski, Y.*; Sibille, R.*; Keller, L.*; et al.
Physical Review Letters, 133(18), p.186704_1 - 186704_6, 2024/11
Times Cited Count:7 Percentile:88.92(Physics, Multidisciplinary)Nirei, Masami; Kofu, Maiko; Nakajima, Kenji; Kikuchi, Tatsuya*; Kawamura, Seiko; Murai, Naoki; Harada, Masahide; Inamura, Yasuhiro
Journal of Neutron Research, 26(2-3), p.75 - 82, 2024/09
Gu, Y. Q.*; Gu, Y. M.*; Liu, F.*; Kawamura, Seiko; Murai, Naoki; Zhao, J.*
Physical Review Letters, 132(24), p.246702_1 - 246702_7, 2024/06
Times Cited Count:2 Percentile:48.32(Physics, Multidisciplinary)Nagl, J.*; Flavin, D.*; Hayashida, S.*; Povarov, K. Y.*; Yan, M.*; Murai, Naoki; Kawamura, Seiko; Simutis, F.*; Hicken, T. J.*; Luetkens, H.*; et al.
Physical Review Research (Internet), 6(2), p.023267_1 - 023267_18, 2024/06
Kofu, Maiko; Kawamura, Seiko; Murai, Naoki; Ishii, Rieko*; Hirai, Daigoro*; Arima, Hiroshi*; Funakoshi, Kenichi*
Physical Review Research (Internet), 6(1), p.013006_1 - 013006_9, 2024/01
Shangguan, Y.*; Bao, S.*; Dong, Z.-Y.*; Xi, N.*; Gao, Y.-P.*; Ma, Z.*; Wang, W.*; Qi, Z.*; Zhang, S.*; Huang, Z.*; et al.
Nature Physics, 19(12), p.1883 - 1889, 2023/09
Times Cited Count:19 Percentile:94.19(Physics, Multidisciplinary)Fujihara, Masayoshi; Hagihara, Masato; Morita, Katsuhiro*; Murai, Naoki; Koda, Akihiro*; Okabe, Hirotaka*; Mitsuda, Setsuo*
Physical Review B, 107(5), p.054435_1 - 054435_8, 2023/02
Times Cited Count:3 Percentile:27.36(Materials Science, Multidisciplinary)The = 1/2 Heisenberg linear chain antiferromagnet is the simplest spin model; nevertheless it serves as a platform for various quantum many-body phenomena. Here, we report the magnetic behavior of a quasi-one-dimensional antiferromagnet KCuPO
H
O. A long-range commensurate antiferromagnetic order with ordered moment 0.31(1)
per spin occurs at
= 11.7(1) K. Above
, the inelastic neutron excitation is characterized by a two spinon continuum. The intrachain interaction
and interchain interaction
are estimated to be 172 K and 4.25(4) K, respectively; thus the ratio of the
/
= 0.0247(3). At lower energies, below
, a spin gap is observed in the dispersive excitations. These results are consistent with characteristics observed in weakly interacting
= 1/2 Heisenberg chain system.
Wu, P.*; Murai, Naoki; Li, T.*; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Kofu, Maiko; Nakajima, Kenji; Xia, K.*; Peng, K.*; Zhang, Y.*; et al.
New Journal of Physics (Internet), 25(1), p.013032_1 - 013032_11, 2023/01
Times Cited Count:0 Percentile:0.00(Physics, Multidisciplinary)Ishii, Yui*; Yamamoto, Arisa*; Sato, Naoki*; Nambu, Yusuke*; Kawamura, Seiko; Murai, Naoki; Ohara, Koji*; Kawaguchi, Shogo*; Mori, Takao*; Mori, Shigeo*
Physical Review B, 106(13), p.134111_1 - 134111_7, 2022/10
Times Cited Count:0 Percentile:0.00(Materials Science, Multidisciplinary)Chen, L.*; Mao, C.*; Chung, J.-H.*; Stone, M. B.*; Kolesnikov, A. I.*; Wang, X.*; Murai, Naoki; Gao, B.*; Delaire, O.*; Dai, P.*
Nature Communications (Internet), 13, p.4037_1 - 4037_7, 2022/07
Times Cited Count:22 Percentile:82.35(Multidisciplinary Sciences)Nakajima, Kenji; Kawamura, Seiko; Kofu, Maiko; Murai, Naoki; Inamura, Yasuhiro; Kikuchi, Tatsuya*; Wakai, Daisuke*
JPS Conference Proceedings (Internet), 33, p.011089_1 - 011089_7, 2021/03
The recent update of AMATERAS, a cold-neutron disk-chopper spectrometer at Japan Proton Accelerator Research Complex (J-PARC), is reported. AMATERAS has been operating for a decade. Since 2017, some updates have been done or are underway, which include installing new detectors, replacing the vacuum system of the scattering chamber, and other works. We are also working on the re-investigation of the resolution function. Demonstration measurements were carried out at 1MW test operations done in 2018 and 2019. Plans of upgrading the spectrometer are currently being considered.
Hao, Y. Q.*; Wo, H. L.*; Gu, Y. M.*; Zhang, X. W.*; Gu, Y. Q.*; Zheng, S. Y.*; Zhao, Y.*; Xu, G. Y.*; Lynn, J. W.*; Nakajima, Kenji; et al.
Science China; Physics, Mechanics & Astronomy, 64(3), p.237411_1 - 237411_6, 2021/03
Times Cited Count:12 Percentile:67.42(Physics, Multidisciplinary)Iida, Kazuki*; Yoshida, Hiroyuki*; Nakao, Akiko*; Jeschke, H. O.*; Iqbal, Y.*; Nakajima, Kenji; Kawamura, Seiko; Munakata, Koji*; Inamura, Yasuhiro; Murai, Naoki; et al.
Physical Review B, 101(22), p.220408_1 - 220408_6, 2020/06
Times Cited Count:28 Percentile:79.33(Materials Science, Multidisciplinary)Crystal and magnetic structures of the mineral centennialite CaCu(OD)
Cl
0.6D
O are investigated by means of synchrotron X-ray diffraction and neutron diffraction measurements complemented by density functional theory (DFT) and pseudofermion functional renormalization group (PFFRG) calculations. In CaCu
(OD)
Cl
0.6D
O, Cu
ions form a geometrically perfect kagome network with antiferromagnetic
. No intersite disorder between Cu
and Ca
ions is detected. CaCu
(OD)
Cl
0.6D
O enters a magnetic long-range ordered state below
= 7.2 K, and the
=0 magnetic structure with negative vector spin chirality is obtained. The ordered moment at 0.3 K is suppressed to 0.58(2)
B. Our DFT calculations indicate the presence of antiferromagnetic
and ferromagnetic
superexchange couplings of a strength which places the system at the crossroads of three magnetic orders (at the classical level) and a spin-
PFFRG analysis shows a dominance of
=0 type magnetic correlations, consistent with and indicating proximity to the observed
=0 spin structure. The results suggest that this material is located close to a quantum critical point and is a good realization of a
-
-
kagome antiferromagnet.
Iida, Kazuki*; Kofu, Maiko; Suzuki, Katsuhiro*; Murai, Naoki; Kawamura, Seiko; Kajimoto, Ryoichi; Inamura, Yasuhiro; Ishikado, Motoyuki*; Hasegawa, Shunsuke*; Masuda, Takatsugu*; et al.
Journal of the Physical Society of Japan, 89(5), p.053702_1 - 053702_5, 2020/05
Times Cited Count:23 Percentile:78.99(Physics, Multidisciplinary)Murai, Naoki; Fukuda, Tatsuo; Nakajima, Masamichi*; Kawamura, Mitsuaki*; Ishikawa, Daisuke*; Tajima, Setsuko*; Baron, A. Q. R.*
Physical Review B, 101(3), p.035126_1 - 035126_6, 2020/01
Times Cited Count:7 Percentile:35.00(Materials Science, Multidisciplinary)We report an inelastic X-ray scattering investigation of phonons in FeSe superconductor. Comparing the experimental phonon dispersion with density functional theory (DFT) calculations in the non-magnetic state, we found a significant disagreement between them. A better overall agreement was obtained by allowing for spin-polarization in DFT calculations, despite the absence of magnetic order in FeSe. This calculation gives a realistic approximation, at DFT level, of the disordered paramagnetic state of FeSe, in which strong spin fluctuations are present.
Ideta, Shinichiro*; Murai, Naoki; Nakajima, Masamichi*; Kajimoto, Ryoichi; Tanaka, Kiyohisa*
Physical Review B, 100(23), p.235135_1 - 235135_7, 2019/12
Times Cited Count:3 Percentile:13.30(Materials Science, Multidisciplinary)Murai, Naoki; Fukuda, Tatsuo; Tajima, Setsuko*; Baron, A. Q. R.*
Hoshako, 32(4), p.199 - 208, 2019/07
Phonon spectra of detwinned SrFeAs
crystals, as measured by inelastic X-ray scattering, show clear anisotropy accompanying the magneto-structural transition at 200 K. We model the modesplitting using magnetic DFT calculations, including a phenomenological reduction in force-constant anisotropy that can be attributed to magnetic fluctuations. This serves as a starting point for a general model of phonons in this material applicable to both magnetic and non-magnetic phase.
Iida, Kazuki*; Nagai, Yuki; Ishida, Shigeyuki*; Ishikado, Motoyuki*; Murai, Naoki; Christianson, A. D.*; Yoshida, Hiroyuki*; Inamura, Yasuhiro; Nakamura, Hiroki; Nakao, Akiko*; et al.
Physical Review B, 100(1), p.014506_1 - 014506_8, 2019/07
Times Cited Count:39 Percentile:83.75(Materials Science, Multidisciplinary)Magnetic excitations and magnetic structure of EuRbFeAs
were investigated by neutron scattering measurements.
Kajimoto, Ryoichi; Ishikado, Motoyuki*; Kira, Hiroshi*; Kaneko, Koji; Nakamura, Mitsutaka; Kamazawa, Kazuya*; Inamura, Yasuhiro; Ikeuchi, Kazuhiko*; Iida, Kazuki*; Murai, Naoki; et al.
Physica B; Condensed Matter, 556, p.26 - 30, 2019/03
Times Cited Count:3 Percentile:13.30(Physics, Condensed Matter)Iida, Kazuki*; Yoshida, Hiroyuki*; Okabe, Hirotaka*; Katayama, Naoyuki*; Ishii, Yuto*; Koda, Akihiro*; Inamura, Yasuhiro; Murai, Naoki; Ishikado, Motoyuki*; Kadono, Ryosuke*; et al.
Scientific Reports (Internet), 9(1), p.1826_1 - 1826_9, 2019/02
Times Cited Count:14 Percentile:64.33(Multidisciplinary Sciences)