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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：64 Percentile：94.61(Physics, Multidisciplinary)
Pb
Sr
Cu
Fe
O
Wakimoto, Shuichi; Hiraka, Haruhiro*; Kudo, Kazutaka*; Okamoto, Daichi*; Nishizaki, Terukazu*; Kakurai, Kazuhisa; Hong, T.*; Zheludev, A.*; Tranquada, J. M.*; Kobayashi, Norio*; et al.
Physical Review B, 82(6), p.064507_1 - 064507_7, 2010/08
Times Cited Count：8 Percentile：36.00(Materials Science, Multidisciplinary)no abstracts in English
PbSrCuO
Hiraka, Haruhiro*; Hayashi, Yoichiro*; Wakimoto, Shuichi; Takeda, Masayasu; Kakurai, Kazuhisa; Adachi, Tadashi*; Koike, Yoji*; Yamada, Ikuya*; Miyazaki, Masanori*; Hiraishi, Masatoshi*; et al.
Physical Review B, 81(14), p.144501_1 - 144501_6, 2010/04
Times Cited Count：16 Percentile：55.47(Materials Science, Multidisciplinary)
Sr
CuO
Matsuda, Masaaki; Fujita, Masaki*; Wakimoto, Shuichi; Fernandez-Baca, J. A.*; Tranquada, J. M.*; Yamada, Kazuyoshi*
Physical Review Letters, 101(19), p.197001_1 - 197001_4, 2008/11
Times Cited Count：51 Percentile：85.47(Physics, Multidisciplinary)We present inelastic neutron scattering experiments on a single-domain crystal of lightly-doped La
Sr
CuO. We find that the magnetic excitation spectrum in this insulating phase with a diagonal incommensurate spin modulation is remarkably similar to that in the superconducting regime, where the spin modulation is bond parallel. In particular, we find that the dispersion slope at low energy is essentially independent of doping and temperature over a significant range. The energy at which the excitations cross the commensurate antiferromagnetic wave vector increases roughly linearly with doping through the underdoped regime.
SrCuOWakimoto, Shuichi; Yamada, Kazuyoshi*; Tranquada, J. M.*; Frost, C. D.*; Swainson, I.*; Birgeneau, R. J.*
Physica C, 460-462(1), p.166 - 169, 2007/09
Times Cited Count：1 Percentile：6.30(Physics, Applied)Spin excitations of overdoped LaSrCuO (
) have been studied by neutron scattering utilizing triple-axis and time-of-flight spectrometers. Low-energy excitation spectra (
meV) for all of the superconducting samples show a maximum around 
meV with a maximum value of dynamic spin susceptibility 
that decreases linearly with 
as doping increases. The magnetic scattering cross section finally disappears at 
, coincident with the disappearance of bulk superconductivity. Time-of-flight measurements for 
and 
shows markedly suppressed magnetic scattering intensities at intermediate energies (20
80meV) in contrast to those of the stripe-ordered La
Ba
CuO. These facts imply a cooperative correlation between the dynamic incommensurate state and the superconductivity.
SrCuOWakimoto, Shuichi; Yamada, Kazuyoshi*; Tranquada, J. M.*; Frost, C. D.*; Birgeneau, R. J.*; Zhang, H.*
Physical Review Letters, 98(24), p.247003_1 - 247003_4, 2007/06
Times Cited Count：97 Percentile：92.36(Physics, Multidisciplinary)Magnetic excitations for energies up to 
meV are studied for over-doped LaSrCuO with and , using time-of-flight neutron spectroscopy. Comparison of spectra integrated over the width of an antiferromagnetic Brillouin zone demonstrates that the magnetic scattering at intermediate energies,
meV, progressively decreases with over-doping. This strongly suggests that the magnetism is not related to Fermi surface nesting, but rather is associated with a decreasing volume fraction of (probably fluctuating) antiferromagnetic bubbles.
SrCuOWakimoto, Shuichi; Birgeneau, R. J.*; Frost, C. D.*; Kagedan, A.*; Kim, H.*; Swainson, I.*; Tranquada, J. M.*; Yamada, Kazuyoshi*; Zhang, H.*
no journal, ,
Spin excitations of LSCO in the overdoped regime has been studied by neutron scattering. Incommensurate excitations around 6 meV which are clearly observed in the sample decrease with 
as doping increases, and finally, become unobservable at coincidentally with the disappearance of bulk superconductivity. High-energy measurements performed at the MAPS spectrometer show remarkably weakened magnetic excitations of the overdoped samples also in the high energy region. These observations are apparently consistent with a microscopic phase separation of the overdoped samples into the superconducting and Fermi liquid phases based on muSR results. In contrast, magnetization measurements of overdoped LSCO with and without Zn impurities have revealed that the superconductivity vanishes in the overdoped regime as a result of a competition between the superconductivity and paramagnetism which is induced even in the Zn-free overdoped LSCO.
SrCuOWakimoto, Shuichi; Yamada, Kazuyoshi*; Tranquada, J. M.*; Frost, C. D.*; Birgeneau, R. J.*; Zhang, H.*
no journal, ,
Neutron scattering experiments have been performed on the overdoped LaSrCuO (). Low energy magnetic excitations ( meV) show incommensurate peaks for the superconducting samples with a maximum at 
meV in the energy spectrum. As doping increases, the maximum of the dynamic susceptibility decreases linearly with and, finally, the low energy excitations become unobservable at coincidentally with the disappearance of bulk superconductivity. Time-of-flight measurements revealed that magnetic excitations for are markedly suppressed in the intermediate energy range (
meV), which is apparently consistent with a microscopic phase separation into a superconducting region which retains the antiferromagnetic correlations and a Fermi liquid region which has no magnetic correlations.
PbSrCuFeOWakimoto, Shuichi; Hiraka, Haruhiro*; Kudo, Kazutaka*; Okamoto, Daichi*; Nishizaki, Terukazu*; Kakurai, Kazuhisa; Hong, T.*; Zheludev, A.*; Tranquada, J. M.*; Kobayashi, Norio*; et al.
no journal, ,
(Sr,Ba)CuOWakimoto, Shuichi; Kakurai, Kazuhisa; Matsuda, Masaaki; Takeda, Masayasu; Fujita, Masaki*; Yamada, Kazuyoshi*; Gu, G.*; Tranquada, J. M.*; Birgeneau, R. J.*; Zhang, H.*
no journal, ,
Polarized neutron scattering exaperiments have been performed on LaBaCuO and La
Sr
CuO with intent to elucidate a possible effects of stripe structure to the spin dynamics. Low energy (
meV) data demonstratre that in the former sample, which has a well-ordered stripe state with Cu spins lying in the CuO
plane at 10 K, spins fluctuate only in the plane. On the other hand, the latter sample, which has very weak stripe order, shows isotropic spin fluctuation. This implies that low energy magnetic excitations are stringly affected by the stripe order.
(Sr,Ba)CuOWakimoto, Shuichi; Fujita, Masaki*; Gu, G.*; Kakurai, Kazuhisa; Matsuda, Masaaki; Takeda, Masayasu; Tranquada, J. M.*; Yamada, Kazuyoshi*; Birgeneau, R. J.*; Frost, C. D.*
no journal, ,
To study effects of the stripe structure to the magnetic excitations in the high- cuprates, we have performed polarized neutron scattering study on LaBaCuO and LaSrCuO. The former shows robust stripe order whereas the latter has only weak order of stripes. The former shows spin fluctuations which are confined in the CuO plane, correspondingly to the confinement of the ordered spins in the plane. The latter shows nearly isotropic spin fluctuations. These observations imply that the low-energy spin excitations are strongly affected by the stripe order, which is important to understand the origin of the universal magnetic dispersion in the high- cuprates.
Sr
CuO
Matsuda, Masaaki; Fujita, Masaki*; Wakimoto, Shuichi; Fernandez-Baca, J. A.*; Tranquada, J. M.*; Yamada, Kazuyoshi*
no journal, ,
We performed inelastic neutron scattering experiments on almost single-domain crystals of lightly-doped LaSrCuO (
=0.021 and 0.04). Despite the rotated incommensurability, we find that the spectrum in this insulating phase with a diagonal incommensurate spin modulation is consistent with the hour-glass dispersion observed in superconducting LaSrCuO and YBaCu
O
, where the spin modulation is bond parallel. In particular, we find that the energy at which the excitations cross the commensurate antiferromagnetic wave vector increases roughly linearly with doping through the underdoped regime.
SrCuOMatsuda, Masaaki; Wakimoto, Shuichi; Fujita, Masaki*; Yamada, Kazuyoshi*; Tranquada, J. M.*
no journal, ,
no abstracts in English
SrCuOMatsuda, Masaaki; Fujita, Masaki*; Wakimoto, Shuichi; Fernandez-Baca, J. A.*; Tranquada, J. M.*; Yamada, Kazuyoshi*
no journal, ,
Neutron scattering experiments were performed in lightly-doped LaSrCuO to study the magnetic excitations in the insulating phase with the diagonal incommensurate spin correlations. It was found that the magnetic excitations at low temperatures are similar to those in the superconducting phase with parallel incommensurate spin correlations. The overall excitation has an hour-glass shape with 
15-25 meV. (
is an energy at which the low-energy excitations cross the antiferromagnetic wave vector.) Furthermore, the effective velocity of the low-energy excitations is approximately independent of doping, so that scales linearly with doping, following the elastic limit of the magnetic incommensurability. This supports the concept that the magnetic excitations evolve directly from the antiferromagnetic insulator.
