Magnetic and quadrupole coupling emerging in NdB with geometrically frustrated orthogonal antiferromagnetic dimer

Metoki, Naoto; Yamauchi, Hiroki; Hagihara, Masato; Watanuki, Ryuta*; Kawamura, Seiko; Kofu, Maiko*; Nakajima, Kenji; Matsuda, Masaaki*

Physical Review B, 111(10), p.104424_1 - 104424_9, 2025/03

https://doi.org/10.1103/PhysRevB.111.104424

Inelastic neutron scattering experiments were carried out to understand the unusual successive order in NdB with the frustrated Shatry-Sutherland (SS) lattice. The pseudo-quartet with and splits into four levels in the magnetically ordered states. The spectra can be explained with the on-site magnetic interaction , the coupling of with quadrupole , and the uniaxial crystalline electric field. The -electron states reproduce the temperature dependences of the in-plane moment which is the primary order parameter, and a weakly induced as the secondary order parameter. The magnetic-quadrupole coupling emerges and play essential role under the geometrical frustration, where the Heisenberg interactions are cancelled out.

Continuum excitations in a spin supersolid on a triangular lattice

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

https://doi.org/10.1103/PhysRevLett.133.186704

Signatures of Kitaev interactions in the van der Waals ferromagnet VI

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

https://doi.org/10.1103/PhysRevLett.132.246702

Recent status of the cryogenic sample environment at the MLF, J-PARC

Ishikado, Motoyuki*; Takahashi, Ryuta*; Yamauchi, Yasuhiro*; Nakamura, Masatoshi*; Ishimaru, Sora*; Yamauchi, Sara*; Kawamura, Seiko; Kira, Hiroshi*; Sakaguchi, Yoshifumi*; Watanabe, Masao; et al.

JPS Conference Proceedings (Internet), 41, p.011010_1 - 011010_7, 2024/05

https://doi.org/10.7566/JPSCP.41.011010

Magnetic boson peak in classical spin glasses

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

https://doi.org/10.1103/PhysRevResearch.6.013006

Field-tuned quantum renormalization of spin dynamics in the honeycomb lattice Heisenberg antiferromagnet YbCl

Sala, G.*; Stone, M. B.*; Halsz, G. B.*; Lumsden, M. D.*; Fay, A, F,*; Pajerowski, D. M.*; Kawamura, Seiko; Kaneko, Koji; Mazzone, D. G.*; Simutis, G.*; et al.

Communications Physics (Internet), 6, p.234_1 - 234_7, 2023/08

https://doi.org/10.1038/s42005-023-01333-7

11th International Workshop on Sample Environment at Scattering Facilities

Kawamura, Seiko

Hamon, 33(1), P. 33, 2023/02

https://doi.org/10.5611/hamon.33.1_33

no abstracts in English

Possible options for efficient wide-band polychromatic measurements using chopper spectrometers at pulsed sources

Nakajima, Kenji; Kikuchi, Tatsuya*; Kawamura, Seiko; Kambara, Wataru*

EPJ Web of Conferences, 272, p.02012_1 - 02012_8, 2022/11

https://doi.org/10.1051/epjconf/202227202012

We will present some of attempts on AMATEAS, a cold-neutron chopper spectrometer at a pulsed source, to increase time-windows at a single-measurement condition. One of ways is that, by allowing interveined trajectories on the time-of-flight diagram, the usable width selectable for is can be increased. Based on our experiences, the conditions of pulse repetition rate multiplication based polychromatic measurements on chopper spectrometers at pulsed sources will be discussed. Optimization of wide-band polychromatic measurements and a generalized formulated condition will be proposed. Application of our idea to existing spectrometers and to the criteria design of an optimized chopper spectrometer will be also discussed with suggesting further possibility to improve efficiency by modifying the pulse shaping chopper.

Magnetic diffuse and quasi-elastic scatterings in frustrated magnet YBaCoO

Soda, Minoru*; Kofu, Maiko; Kawamura, Seiko; Asai, Shinichiro*; Masuda, Takatsugu*; Yoshizawa, Hideki*; Furukawa, Hazuki*

Journal of the Physical Society of Japan, 91(9), p.094707_1 - 094707_5, 2022/09

https://doi.org/10.7566/JPSJ.91.094707

Magnetic Bragg peak enhancement under ultrasound injection

Shamoto, Shinichi*; Akatsu, Mitsuhiro*; Matsuura, Masato*; Kawamura, Seiko; Harii, Kazuya*; Ono, Masao*; Chang, L.-J.*; Ito, Takashi; Nemoto, Yuichi*; Ieda, Junichi

Physical Review Research (Internet), 4(1), p.013245_1 - 013245_7, 2022/03

https://doi.org/10.1103/PhysRevResearch.4.013245

Ultrasound injection effect on a magnetic Bragg peak of yttrium iron garnet has been studied by quasielastic neutron scattering. The magnetic Bragg peak is vastly enhanced with decreasing temperature. The energy width increases proportionally to the square root of the sample temperature increase induced by the ultrasound injection. Because the magnetic Bragg peak is enhanced by the lattice vibration, the enhancement is expected to relate to the spin-lattice coupling closely. An observed sharp drop above 100 K in the longitudinal mode suggests the degradation of the spin-lattice coupling. It is consistent with the decline of spin Seebeck effect with increasing temperature above 100 K, proving the degradation mechanism by the spin-lattice coupling.