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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:0 Percentile:65.86(Physics, Multidisciplinary)Elyasi, M.*; Saito, Eiji; Bauer, G. E. W.*
Physical Review B, 105(5), p.054403_1 - 054403_12, 2022/02
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:9 Percentile:62.96(Physics, Multidisciplinary)Bauer, R.*; Tse, J. S.*; Komatsu, Kazuki*; Machida, Shinichi*; Hattori, Takanori
Nature, 585(7825), p.E9 - E10, 2020/09
Times Cited Count:4 Percentile:87.39(Multidisciplinary Sciences)Pressure-induced structural transformations in deuterated crystalline ice-Ih were studied in-situ at 100 K using neutron diffraction. Very long relaxation time was allowed between small pressure increments to promote transformations to the thermodynamic stable high pressure crystalline phases. The results contradict a recent report in which measurements under similar temperature and pressure environment show successive crystal-to-crystal transformations (Tulk, et.al., Nature 2019). Instead, ice Ih was found to transform partially to an amorphous form (high density amorphous, HDA) at 1.0 GPa and then ice VII started to emerge at 1.5 GPa, a pressure substantially lower than all earlier studies. During this pressure interval, crystalline ice Ih or ice VII co-exist with HDA. The ice VII formed is stable upon pressure release down to 0.1 GPa. The very low compression rate has a profound effect on the crystallinity in the amorphous regime. Gathering all the existing experimental evidences allows an unambiguous description of the phenomenon of pressure induced amorphization. The onset of the phase transition is triggered by a shear instability of the ice lattice. The co-existence ice VII with HDA, instead of the equilibrium thermodynamic stable and proton-ordered ice-VIII under the same pressure-temperature condition reveals at low temperature there is insufficient thermal energy to overcome the substantial geometrical rearrangement from a single proton disordered H-bond network to an interpenetrating proton ordered H-bond crystalline network. Thus, leaving the proton disordered H-network intact. The analysis shows unequivocally that the structure obtained from the compression of ice is controlled by kinetics and dependent on the temperature.
Nambu, Yusuke*; Barker, J.*; Okino, Yuki*; Kikkawa, Takashi*; Shiomi, Yuki*; Enderle, M.*; Weber, T.*; Winn, B.*; Graves-Brook, M.*; Tranquada, J. M.*; et al.
Physical Review Letters, 125(2), p.027201_1 - 027201_6, 2020/07
Times Cited Count:35 Percentile:93.71(Physics, Multidisciplinary)Sakai, Hironori; Tokunaga, Yo; Haga, Yoshinori; Kambe, Shinsaku; Ramakrishna, S. K.*; Reyes, A. P.*; Rosa, P. F. S.*; Ronning, F.*; Thompson, J. D.*; Fisk, Z.*; et al.
JPS Conference Proceedings (Internet), 30, p.011169_1 - 011169_6, 2020/03
Uranium disulfide -US showing a semimetal-to-semiconductor crossover has been investigated by the nuclear magnetic resonance (NMR) technique for S nuclei with the nuclear spin of . Since the natural concentration 0.76% of NMR active S nuclei is too dilute, the isotopic enrichment to 50% has been carried out for the single crystal growth. The S NMR spectra have been successfully obtained using a single crystal of -US with external fields along the crystallographic axis. The S sites assignments have been made based on these NMR spectra.
Oyanagi, Koichi*; Takahashi, Saburo*; Cornelissen, L. J.*; Shan, J.*; Daimon, Shunsuke*; Kikkawa, Takashi*; Bauer, G. E. W.*; Van Wees, B. J.*; Saito, Eiji
Nature Communications (Internet), 10, p.4740_1 - 4740_6, 2019/10
Times Cited Count:33 Percentile:88.92(Multidisciplinary Sciences)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:29 Percentile:85.61(Materials Science, Multidisciplinary)Magnetic excitations and magnetic structure of EuRbFeAs were investigated by neutron scattering measurements.
Flavigny, F.*; Elseviers, J.*; Andreyev, A. N.; Bauer, C.*; Bildstein, V.*; Blazhev, A.*; 31 of others*
Physical Review C, 99(5), p.054332_1 - 054332_6, 2019/05
Times Cited Count:7 Percentile:64.83(Physics, Nuclear)Dioguardi, A. P.*; Yasuoka, Hiroshi*; Thomas, S. M.*; Sakai, Hironori; Cary, S. K.*; Kozimor, S. A.*; Albrecht-Schmitt, T. E.*; Choi, H. C.*; Zhu, J.-X.*; Thompson, J. D.*; et al.
Physical Review B, 99(3), p.035104_1 - 035104_6, 2019/01
Times Cited Count:5 Percentile:38.09(Materials Science, Multidisciplinary)We present a detailed nuclear magnetic resonance (NMR) study of Pu in bulk and powdered single-crystal plutonium tetraboride (PuB), which has recently been investigated as a potential correlated topological insulator. The Pu NMR spectra are consistent with axial symmetry of the shift tensor showing for the first time that Pu NMR can be observed in an anisotropic environment and up to room temperature. The temperature dependence of the Pu shift, combined with a relatively long spin-lattice relaxation time (), indicate that PuB adopts a nonmagnetic state with gaplike behavior consistent with our density functional theory calculations. The temperature dependencies of the NMR Knight shift and imply bulk gaplike behavior confirming that PuB is a good candidate topological insulator.
Sakai, Hironori; Hattori, Taisuke; Tokunaga, Yo; Kambe, Shinsaku; Ghimire, N. J.*; Ronning, F.*; Bauer, E. D.*; Thompson, J. D.*
Journal of Physics; Conference Series, 868(1), p.012012_1 - 012012_5, 2017/07
Times Cited Count:1 Percentile:49.82Al NMR experiments have been performed using a single crystal of CeRhAlSi. In the paramagnetic state, Knight shifts, quadrupolar frequency, and asymmetric parameter of electrical field gradient on the Al sites have been determined, which has a local orthorhombic symmetry. The transferred hyperfine coupling constants are also determined. The relaxation rates suggest that 4 electrons behave as local moments in the high temperatures. From the NMR spectral analyses, the antiferromagnetic structures are discussed.
Sakai, Hironori; Ronning, F.*; Hattori, Takanori; Tokunaga, Yo; Kambe, Shinsaku; Zhu, J.-X.*; Wakeham, N.*; Yasuoka, Hiroshi; Bauer, E. D.*; Thompson, J. D.*
Journal of Physics; Conference Series, 807(3), p.032001_1 - 032001_6, 2017/04
Times Cited Count:2 Percentile:55We have used nuclear quadrupole resonance (NQR) to probe microscopically the response of a prototypical quantum critical metal CeCoIn to substitutions of small amounts of Cd for In. Approximately half of the Cd substituents induce local Ce moments in their close proximity, as observed by site-dependent longitudinal nuclear spin relaxation rates . To reaffirm that localized moments are induced around the Cd substituents, we find a Gaussian spin-echo decay rate of transverse nuclear spin relaxation. Further, for the NQR subpeak is found to be proportional to temperatures, again indicating local moments fluctuations around the Cd substituents, while that for the NQR main peak shows a -dependence. The latter temperature dependence is close to 0.75 in pure CeCoIn and indicates that the bulk electronic state is located close to a two dimensional quantum critical instability.
Kikkawa, Takashi*; Shen, K.*; Flebus, B.*; Duine, R. A.*; Uchida, Kenichi*; Qiu, Z.*; Bauer, G. E. W.*; Saito, Eiji
Physical Review Letters, 117(20), p.207203_1 - 207203_6, 2016/11
Times Cited Count:131 Percentile:97.71(Physics, Multidisciplinary)Hou, D.*; Qiu, Z.*; Iguchi, Ryo*; Sato, Koji*; Vehstedt, E. K.*; Uchida, Kenichi*; Bauer, G. E. W.*; Saito, Eiji
Nature Communications (Internet), 7, p.12265_1 - 12265_6, 2016/07
Times Cited Count:14 Percentile:64.7(Multidisciplinary Sciences)Chen, Y.-T.*; Takahashi, Saburo*; Nakayama, Hiroyasu*; Althammer, M.*; Goennenwein, S. T. B.*; Saito, Eiji; Bauer, G. E. W.*
Journal of Physics; Condensed Matter, 28(10), p.103004_1 - 103004_15, 2016/03
Times Cited Count:77 Percentile:62.39(Physics, Condensed Matter)We review the so-called spin Hall magnetoresistance (SMR) in bilayers of a magnetic insulator and a metal, in which spin currents are generated in the normal metal by the spin Hall effect. The associated angular momentum transfer to the ferromagnetic layer and thereby the electrical resistance is modulated by the angle between the applied current and the magnetization direction. The SMR provides a convenient tool to non-invasively measure the magnetization direction and spin-transfer torque to an insulator. We introduce the minimal theoretical instruments to calculate the SMR, i.e. spin diffusion theory and quantum mechanical boundary conditions. This leads to a small set of parameters that can be fitted to experiments. We discuss the limitations of the theory as well as alternative mechanisms such as the ferromagnetic proximity effect and Rashba spin-orbit torques, and point out new developments.
Geprgs, S.*; Kehlberger, A.*; Coletta, F.*; Qiu, Z.*; Guo, E.-J.*; Schulz, T.*; Mix, C.*; Meyer, S.*; Kamra, A.*; Althammer, M.*; et al.
Nature Communications (Internet), 7, p.10452_1 - 10452_6, 2016/02
Times Cited Count:137 Percentile:97.31(Multidisciplinary Sciences)Sakai, Hironori; Hattori, Taisuke; Tokunaga, Yo; Kambe, Shinsaku; Ghimire, N. J.*; Ronning, F.*; Bauer, E. D.*; Thompson, J. D.*
Physical Review B, 93(1), p.014402_1 - 014402_9, 2016/01
Times Cited Count:2 Percentile:10.73(Materials Science, Multidisciplinary)Al nuclear magnetic resonance (NMR) experiments have been performed on a single crystal of CeRhAlSi, which is an antiferromagnetic Kondo-lattice compound with successive antiferromagnetic transitions of =14 K and =9 K at zero external field. In the paramagnetic state, the Knight shifts, quadrupolar frequency, and asymmetric parameter of electrical field gradient on the Al sites have been determined, which have local orthorhombic symmetry. The transferred hyperfine coupling constants are also determined. Analysis of the NMR spectra indicates that a commensurate antiferromagnetic structure exists below , but an incommensurate modulation of antiferromagnetic moments is present in the antiferromagnetic state between and . The spin-lattice relaxation rate suggests that the electrons behave as local moments at temperatures above .
Sakai, Hironori; Ronning, F.*; Zhu, J.-X.*; Wakeham, N.*; Yasuoka, Hiroshi; Tokunaga, Yo; Kambe, Shinsaku; Bauer, E. D.*; Thompson, J. D.*
Physical Review B, 92(12), p.121105_1 - 121105_5, 2015/09
Times Cited Count:18 Percentile:60.6(Materials Science, Multidisciplinary)Chemical substitutions are used commonly to tune a magnetic transition to zero temperature, but the resulting non-Fermi liquid (NFL) behavior is non-universal. We have used nuclear quadrupole resonance (NQR) to probe microscopically the response of a prototypical quantum-critical metal CeCoIn to substitutions of small amounts of Sn and Cd for In. These substituents induce very different local electronic environments as observed by site dependent spin lattice relaxation rates that influence the NFL behavior. The effects found here illustrate the need for care in interpreting NFL properties determined by macroscopic measurements.
Bottoni, S.*; Leoni, S.*; Fornal, B.*; Raabe, R.*; Rusek, K.*; Benzoni, G.*; Bracco, A.*; Crespi, F. C. L.*; Morales, A. I.*; Bednarczyk, P.*; et al.
Physical Review C, 92(2), p.024322_1 - 024322_8, 2015/08
Times Cited Count:19 Percentile:78.31(Physics, Nuclear)Schreier, M.*; Bauer, G. E. W.*; Vasyuchka, V.*; Flipse, J.*; Uchida, Kenichi*; Lotze, J.*; Lauer, V.*; Chumak, A.*; Serga, A.*; Daimon, Shunsuke*; et al.
Journal of Physics D; Applied Physics, 48(2), p.025001_1 - 025001_5, 2015/01
Times Cited Count:53 Percentile:87.63(Physics, Applied)