Ideguchi, Eiji*; Kibdi, T.*; Dowie, J. T. H.*; Hoang, T. H.*; Kumar Raju, M.*; Aoi, Nori*; Mitchell, A. J.*; Stuchbery, A. E.*; Shimizu, Noritaka*; Utsuno, Yutaka; et al.
Physical Review Letters, 128(25), p.252501_1 - 252501_6, 2022/06
no abstracts in English
Masuda, Hiroto*; Seki, Takeshi*; Yamane, Yuta*; Modak, R.*; Uchida, Kenichi*; Ieda, Junichi; Lau, Y.-C.*; Fukami, Shunsuke*; Takanashi, Koki
Physical Review Applied (Internet), 17(5), p.054036_1 - 054036_9, 2022/05
The antisymmetric interlayer exchange coupling (AIEC) was recently discovered, playing pivotal roles in magnetization switching of a synthetic antiferromagnet (SAF) through inducing magnetization canting. Large AIEC is reported for perpendicularly magnetized Pt/Co/Ir/Co/Pt with wedge-shaped layers. The effective field of the AIEC is related with symmetric interlayer exchange coupling, providing guides to enhance the AIEC. We develop an extended Stoner-Wohlfarth model for a SAF, revealing key factors in its magnetization switching. Combining the theoretical knowledge and the experimental results, perpendicular magnetization switching is achieved solely by an in-plane magnetic field.
Nakata, Koki; Ohnuma, Yuichi*; Kim, S. K.*
Physical Review B, 105(18), p.184409_1 - 184409_7, 2022/05
We show that the ratio of the thermal to spin transport coefficient of magnons in insulating magnets exhibits a different behavior from the linear response and the universal law breaks down in the strong nonlinear regime.
Do, S.-H.*; Kaneko, Koji; Kajimoto, Ryoichi; Kamazawa, Kazuya*; Stone, M. B.*; Lin, J. Y. Y.*; Ito, Shinichi*; Masuda, Takatsugu*; Samolyuk, G. D.*; Dagotto, E.*; et al.
Physical Review B, 105(18), p.L180403_1 - L180403_6, 2022/05
Nakata, Koki; Onuma, Yuichi*
Physical Review B, 105(14), p.144436_1 - 144436_7, 2022/04
Using a junction of the ferromagnetic insulators irradiated by linearly polarized laser, we propose a method for the generation of dc and ac spin currents of magnons across the junction interface, and provide an analytical formula for magnon transport induced by the inversion symmetry breaking.
Mattan, K.*; Ono, Toshio*; Kawamura, Seiko; Nakajima, Kenji; Nambu, Yusuke*; Sato, Taku*
Physical Review B, 105(13), p.134403_1 - 134403_8, 2022/04
Spin dynamics of the spin-1/2 kagome-lattice antiferromagnet CsCuSnF was studied using high-resolution, time-of-flight inelastic neutron scattering. The flat mode, a characteristic of the frustrated kagome antiferromagnet, and the low-energy dispersive mode, which is dominated by magnons, can be well described by the linear spin-wave theory. However, the theory fails to describe three weakly dispersive modes between 9 and 14 meV. These modes could be attributed to two-spinon bound states, which decay into free spinons away from the zone center and at a high temperature, giving rise to continuum scattering.
Suenaga, Daiki*; Araki, Yasufumi; Suzuki, Kei; Yasui, Shigehiro*
Physical Review D, 105(7), p.074028_1 - 074028_19, 2022/04
We propose a new mechanism of the heavy-quark spin polarization (HQSP) in quark matter induced by the Kondo effect under an external magnetic field. The Kondo effect is caused by a condensate between a heavy and a light quark called the Kondo condensate leading to a mixing of the heavy- and light-quark spins. Thus, the HQSP is driven through the Kondo effect from light quarks coupling with the magnetic field in quark matter. For demonstration, we employ the Nambu-Jona-Lasinio type model under a magnetic field and investigate the HQSP within the linear response theory with vertex corrections required by the electromagnetic gauge invariance. As a result, we find that the HQSP arises significantly with the appearance of the Kondo effect. Our findings are testable in future sign-problem-free lattice simulations.
Yamane, Yuta*; Fukami, Shunsuke*; Ieda, Junichi
Physical Review Letters, 128(14), p.147201_1 - 147201_6, 2022/04
We extend the theory of emergent inductance, which has recently been discovered in spiral magnets, to arbitrary magnetic textures by taking into account spin-orbit couplings arising in the absence of spatial inversion symmetry. We propose a new concept of spin-orbit emergent inductance, which can be formulated as originating from a dynamical Aharonov-Casher phase of an electron in ferromagnets. The spin-orbit emergent inductance universally arises in the coexistence of magnetism and the spin-orbit couplings, even with spatially uniform magnetization, allowing its stable operation in wide ranges of temperature and frequency. Revisiting the widely studied systems involving ferromagnets with spatial inversion asymmetry, with the new perspective offered by our work, will lead to opening a new paradigm in the study of spin-orbit physics and the spintronics-based power management in ultrawideband frequency range.
Kubota, Takahide*; Takano, Daichi*; Kota, Yohei*; Mohanty, S.*; Ito, Keita*; Matsuki, Mitsuhiro*; Hayashida, Masahiro*; Sun, M.*; Takeda, Yukiharu; Saito, Yuji; et al.
Physical Review Materials (Internet), 6(4), p.044405_1 - 044405_12, 2022/04
Fujimori, Shinichi; Takeda, Yukiharu; Yamagami, Hiroshi; Pospil, J.*; Yamamoto, Etsuji; Haga, Yoshinori
Physical Review B, 105(11), p.115128_1 - 115128_6, 2022/03
Zhao, Y.*; Suzuki, T.*; Iimori, T.*; Kim, H.-W.*; Ahn, J. R.*; Horio, Masafumi*; Sato, Yusuke*; Fukaya, Yuki; Kanai, T.*; Okazaki, K.*; et al.
Physical Review B, 105(11), p.115304_1 - 115304_8, 2022/03
no abstracts in English
Kitamura, Noritaka*; Wimmer, K.*; Miyagi, Takayuki*; Poves, A.*; Shimizu, Noritaka*; Tostevin, J. A.*; Bader, V. M.*; Bancroft, C.*; Barofsky, D.*; Baugher, T.*; et al.
Physical Review C, 105(3), p.034318_1 - 034318_17, 2022/03
no abstracts in English
Aritomo, Yoshihiro*; Iwamoto, Akira*; Nishio, Katsuhisa; Ota, Masahisa*
Physical Review C, 105(3), p.034604_1 - 034604_8, 2022/03
Yang, Z.*; Wang, G.-J.*; Wu, J.-J.*; Oka, Makoto; Zhu, S.-L.*
Physical Review Letters, 128(11), p.112001_1 - 112001_6, 2022/03
A novel framework is proposed to extract near-threshold resonant states from finite-volume energy levels of lattice QCD and is applied to elucidate structures of the positive parity . The quark model, the quark-pair-creation mechanism and interaction are incorporated into the Hamiltonian effective field theory. The bare states are almost purely given by the states with heavy-quark spin bases. The physical and are the mixtures of bare core and component, while the and are almost dominated by bare . Furthermore, our model well reproduce the clear level crossing of the with the scattering state at a finite volume.
Hashimoto, Tadashi; Tanida, Kiyoshi; 68 of others*
Physical Review Letters, 128(11), p.112503_1 - 112503_6, 2022/03
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
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.
Watanabe, Masari*; Kurita, Nubuyuki*; Tanaka, Hidekazu*; Ueno, Wataru*; Matsui, Kazuki*; Goto, Takayuki*; Hagihara, Masato
Physical Review B, 105(5), p.054414_1 - 054414_12, 2022/02
Saito, Mutsuki*; Takagishi, Ryunosuke*; Kurita, Nubuyuki*; Watanabe, Masari*; Tanaka, Hidekazu*; Nomura, Ryuji*; Fukumoto, Yoshiyuki*; Ikeuchi, Kazuhiko*; Kajimoto, Ryoichi
Physical Review B, 105(6), p.064424_1 - 064424_15, 2022/02
Tajima, Hiroyuki*; Sekino, Yuta*; Uchino, Shun
Physical Review B, 105(6), p.064508_1 - 064508_9, 2022/02
We theoretically investigate optical bulk spin transport properties in a spin- topological Fermi superfluid. We specifically consider a one-dimensional system with an inter-spin -wave interaction, which can be realized in ultracold-atom experiments. Developing the BCS-Leggett theory to describe the BCS to Bose-Einstein condensate evolution and the Z topological phase transition in this system, we show how the spin transport reflects these many-body aspects. We find that the optical spin conductivity, which is a small AC response of a spin current, shows the spin-gapped spectrum in the wide parameter region and the gap closes at the Z topological phase transition point. Moreover, the validity of the low-energy effective model of the Majorana zero mode is discussed along the BCS-BEC evolution in connection with the scale invariance at -wave unitarity.
Tanaka, Shoya*; Hirose, Kentaro; Nishio, Katsuhisa; Kean, K. R.*; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Aritomo, Yoshihiro*
Physical Review C, 105(2), p.L021602_1 - L021602_5, 2022/02