by Wakimoto, S., Ishii, K., Kimura, H., Fujita, M., Dellea, G., Kummer, K., Braicovich, L., Ghiringhelli, G. and Debeer-Schmitt, L. M. and Granroth, G. E.
Abstract:
We have performed neutron inelastic scattering and resonant inelastic x-ray scattering (RIXS) at the Cu-L-3 edge to study high-energy magnetic excitations at energy transfers of more than 100 meV for overdoped La2-xSrxCuO4 with x = 0.25 (T-c = 15 K) and x = 0.30 (nonsuperconducting) using identical single-crystal samples for the two techniques. From constant-energy slices of neutron-scattering cross sections, we have identified magnetic excitations up to similar to 250 meV for x = 0.25. Although the width in the momentum direction is large, the peak positions along the (pi, pi) direction agree with the dispersion relation of the spin wave in the nondoped La2CuO4 (LCO), which is consistent with the previous RIXS results of cuprate superconductors. Using RIXS at the Cu-L-3 edge, we have measured the dispersion relations of the so-called paramagnon mode along both (pi, pi) and (pi, 0) directions. Although in both directions the neutron and RIXS data connect with each other and the paramagnon along (pi, 0) agrees well with the LCO spin-wave dispersion, the paramagnon in the (pi, pi) direction probed by RIXS appears to be less dispersive and the excitation energy is lower than the spin wave of LCO near (pi/2, pi/2). Thus, our results indicate consistency between neutron inelastic scattering and RIXS, and elucidate the entire magnetic excitation in the (pi, pi) direction by the complementary use of two probes. The polarization dependence of the RIXS profiles indicates that appreciable charge excitations exist in the same energy range of magnetic excitations, reflecting the itinerant character of the overdoped sample. A possible anisotropy in the charge excitation intensity might explain the apparent differences in the paramagnon dispersion in the (pi, pi) direction as detected by the x-ray scattering.
Reference:
High-energy magnetic excitations in overdoped La2-xSrxCuO4 studied by neutron and resonant inelastic x-ray scattering (Wakimoto, S., Ishii, K., Kimura, H., Fujita, M., Dellea, G., Kummer, K., Braicovich, L., Ghiringhelli, G. and Debeer-Schmitt, L. M. and Granroth, G. E.), In PHYSICAL REVIEW B, AMER PHYSICAL SOC, volume 91, 2015.
Bibtex Entry:
@article{ ISI:000354984800004,
Author = {Wakimoto, S. and Ishii, K. and Kimura, H. and Fujita, M. and Dellea, G.
   and Kummer, K. and Braicovich, L. and Ghiringhelli, G. and
   Debeer-Schmitt, L. M. and Granroth, G. E.},
Title = {{High-energy magnetic excitations in overdoped La2-xSrxCuO4 studied by
   neutron and resonant inelastic x-ray scattering}},
Journal = {{PHYSICAL REVIEW B}},
Year = {{2015}},
Volume = {{91}},
Number = {{18}},
Month = {{MAY 21}},
Abstract = {{We have performed neutron inelastic scattering and resonant inelastic
   x-ray scattering (RIXS) at the Cu-L-3 edge to study high-energy magnetic
   excitations at energy transfers of more than 100 meV for overdoped
   La2-xSrxCuO4 with x = 0.25 (T-c = 15 K) and x = 0.30
   (nonsuperconducting) using identical single-crystal samples for the two
   techniques. From constant-energy slices of neutron-scattering cross
   sections, we have identified magnetic excitations up to similar to 250
   meV for x = 0.25. Although the width in the momentum direction is large,
   the peak positions along the (pi, pi) direction agree with the
   dispersion relation of the spin wave in the nondoped La2CuO4 (LCO),
   which is consistent with the previous RIXS results of cuprate
   superconductors. Using RIXS at the Cu-L-3 edge, we have measured the
   dispersion relations of the so-called paramagnon mode along both (pi,
   pi) and (pi, 0) directions. Although in both directions the neutron and
   RIXS data connect with each other and the paramagnon along (pi, 0)
   agrees well with the LCO spin-wave dispersion, the paramagnon in the
   (pi, pi) direction probed by RIXS appears to be less dispersive and the
   excitation energy is lower than the spin wave of LCO near (pi/2, pi/2).
   Thus, our results indicate consistency between neutron inelastic
   scattering and RIXS, and elucidate the entire magnetic excitation in the
   (pi, pi) direction by the complementary use of two probes. The
   polarization dependence of the RIXS profiles indicates that appreciable
   charge excitations exist in the same energy range of magnetic
   excitations, reflecting the itinerant character of the overdoped sample.
   A possible anisotropy in the charge excitation intensity might explain
   the apparent differences in the paramagnon dispersion in the (pi, pi)
   direction as detected by the x-ray scattering.}},
Publisher = {{AMER PHYSICAL SOC}},
Address = {{ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA}},
Type = {{Article}},
Language = {{English}},
Affiliation = {{Wakimoto, S (Corresponding Author), Japan Atom Energy Agcy, Quantum Beam Sci Ctr, Tokai, Ibaraki 3191195, Japan.
   Wakimoto, S., Japan Atom Energy Agcy, Quantum Beam Sci Ctr, Tokai, Ibaraki 3191195, Japan.
   Ishii, K., Japan Atom Energy Agcy, SPring 8, Mikazuki, Hyogo 6795148, Japan.
   Kimura, H., Tohoku Univ, Inst Multidisciplinary Res Adv Mat, Sendai, Miyagi 9808577, Japan.
   Fujita, M., Tohoku Univ, Inst Mat Res, Sendai, Miyagi 9808577, Japan.
   Dellea, G.; Braicovich, L.; Ghiringhelli, G., Politecn Milan, CNR SPIN, I-20133 Milan, Italy.
   Dellea, G.; Braicovich, L.; Ghiringhelli, G., Politecn Milan, Dipartimento Fis, I-20133 Milan, Italy.
   Kummer, K., European Synchrotron Radiat Facil, F-38043 Grenoble, France.
   Debeer-Schmitt, L. M., Oak Ridge Natl Lab, Instrument & Source Div, Oak Ridge, TN 37831 USA.
   Granroth, G. E., Oak Ridge Natl Lab, Quantum Condensed Matter Div, Oak Ridge, TN 37831 USA.
   Granroth, G. E., Oak Ridge Natl Lab, Neutron Data Anal & Visualizat Div, Oak Ridge, TN 37831 USA.}},
DOI = {{10.1103/PhysRevB.91.184513}},
Article-Number = {{184513}},
ISSN = {{2469-9950}},
EISSN = {{2469-9969}},
Keywords-Plus = {{SPIN EXCITATIONS; TRANSITION-TEMPERATURE}},
Research-Areas = {{Materials Science; Physics}},
Web-of-Science-Categories  = {{Materials Science, Multidisciplinary; Physics, Applied; Physics,
   Condensed Matter}},
ResearcherID-Numbers = {{Ishii, Kenji/G-3453-2017
   Ghiringhelli, Giacomo/D-1159-2014
   Granroth, Garrett E/G-3576-2012
   DeBeer-Schmitt, Lisa/I-3313-2015
   Fujita, Masaki/D-8430-2013
   Wakimoto, Shuichi/V-8177-2019
   }},
ORCID-Numbers = {{Ishii, Kenji/0000-0002-6465-8202
   Ghiringhelli, Giacomo/0000-0003-0867-7748
   Granroth, Garrett E/0000-0002-7583-8778
   DeBeer-Schmitt, Lisa/0000-0001-9679-3444
   Braicovich, Lucio/0000-0001-6548-9140}},
Funding-Acknowledgement = {{Scientific User Facilities Division, Office of Basic Energy Sciences, US
   Department of EnergyUnited States Department of Energy (DOE); 
   {[}25390132];  {[}35400333];  {[}24340064]}},
Funding-Text = {{Authors thank R. Kajimoto, M. Matsuda, M. Matsuura, K. Nakajima, T.
   Tohyama, and K. Yamada for invaluable discussion. Authors also
   acknowledge L. J. Santodonate and M. Matsuda for their assistance in
   using CG1B at ORNL. This work was supported by Grant-In-Aid for
   Scientific Research (C) Grants No. 25390132 and No. 35400333, and by
   Grant-In-Aid for Scientific Research (B) Grant No. 24340064. Part of the
   research conducted at ORNL's High Flux Isotope Reactor and Spallation
   Neutron Source was sponsored by the Scientific User Facilities Division,
   Office of Basic Energy Sciences, US Department of Energy. The RIXS
   experiments were performed using the AXES instrument at ID08 at the
   European Synchrotron Radiation Facility (ESRF). We acknowledge ESRF for
   provision of synchrotron radiation facilities and we would like to thank
   N. B. Brookes for the support at ID08.}},
Number-of-Cited-References = {{26}},
Times-Cited = {{16}},
Usage-Count-Last-180-days = {{0}},
Usage-Count-Since-2013 = {{36}},
Journal-ISO = {{Phys. Rev. B}},
Doc-Delivery-Number = {{CI7ZC}},
Unique-ID = {{ISI:000354984800004}},
OA = {{Green Published, Bronze}},
DA = {{2020-12-22}},
}

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