Mobile orbitons in Ca2CuO3: Crucial role of Hund’s exchange

@article{ ISI:000531732200003,
Author = {Fumagalli, R. and Heverhagen, J. and Betto, D. and Arpaia, R. and Rossi,
   M. and Di Castro, D. and Brookes, N. B. and Sala, M. Moretti and
   Daghofer, M. and Braicovich, L. and Wohlfeld, K. and Ghiringhelli, G.},
Title = {{Mobile orbitons in Ca2CuO3: Crucial role of Hund's exchange}},
Journal = {{PHYSICAL REVIEW B}},
Year = {{2020}},
Volume = {{101}},
Number = {{20}},
Month = {{MAY 12}},
Abstract = {{We investigate the CuL3 edge resonant inelastic x-ray scattering (RIXS)
   spectra of a quasi-1D antiferromagnet Ca2CuO3. In addition to the
   magnetic excitations, which are well-described by the two-spinon
   continuum, we observe two dispersive orbital excitations, the 3d(xy) and
   the 3d(yz) orbitons. We carry out a quantitative comparison of the RIXS
   spectra, obtained with two distinct incident polarizations, with a
   theoretical model. We show that any realistic spin-orbital model needs
   to include a finite, but realistic, Hund's exchange J(H) approximate to
   0.5 eV. Its main effect is an increase in orbiton velocities, so that
   their theoretically calculated values match those observed
   experimentally. Even though Hund's exchange also mediates some
   interaction between spinon and orbiton, the picture of spin-orbit
   separation remains intact and describes orbiton motion in this compound.}},
Publisher = {{AMER PHYSICAL SOC}},
Address = {{ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA}},
Type = {{Article}},
Language = {{English}},
Affiliation = {{Wohlfeld, K (Corresponding Author), Univ Warsaw, Fac Phys, Inst Theoret Phys, Pasteura 5, PL-02093 Warsaw, Poland.
   Fumagalli, R.; Arpaia, R.; Rossi, M.; Sala, M. Moretti; Braicovich, L.; Ghiringhelli, G., Politecn Milan, Dipartimento Fis, Piazza Leonardo da Vinci 32, I-20133 Milan, Italy.
   Heverhagen, J.; Daghofer, M., Univ Stuttgart, Inst Funct Matter & Quantum Technol, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
   Betto, D.; Brookes, N. B.; Braicovich, L., European Synchrotron, ESRF, BP 220, F-38043 Grenoble, France.
   Arpaia, R., Chalmers Univ Technol, Dept Microtechnol & Nanosci, Quantum Device Phys Lab, SE-41296 Gothenburg, Sweden.
   Di Castro, D., Univ Roma Tor Vergata, Dipartimento Ingn Civile & Ingn Informat, Via Politecn 1, I-00133 Rome, Italy.
   Di Castro, D., Univ Roma Tor Vergata, DICII, CNR Spin, Via Politecn 1, I-00133 Rome, Italy.
   Daghofer, M., Univ Stuttgart, Ctr Integrated Quantum Sci & Technol, Pfaffenwaldring 57, Stuttgart 70550, Germany.
   Wohlfeld, K., Univ Warsaw, Fac Phys, Inst Theoret Phys, Pasteura 5, PL-02093 Warsaw, Poland.
   Ghiringhelli, G., Politecn Milan, Dipartimento Fis, CNR SPIN, Milan 20133, Italy.
   Betto, D., Max Planck Inst Solid State Phys, Heisenbergstr 1, D-70569 Stuttgart, Germany.
   Rossi, M., SLAC Natl Accelerator Lab, Stanford Inst Mat & Energy Sci, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA.
   Rossi, M., Stanford Univ, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA.}},
DOI = {{10.1103/PhysRevB.101.205117}},
Article-Number = {{205117}},
ISSN = {{2469-9950}},
EISSN = {{2469-9969}},
Keywords-Plus = {{SPIN-CHARGE SEPARATION; EXCITATIONS}},
Research-Areas = {{Materials Science; Physics}},
Web-of-Science-Categories  = {{Materials Science, Multidisciplinary; Physics, Applied; Physics,
   Condensed Matter}},
Author-Email = {{krzysztof.wohlfeld@fuw.edu.pl
   giacomo.ghiringhelli@polimi.it}},
ResearcherID-Numbers = {{Ghiringhelli, Giacomo/D-1159-2014
   }},
ORCID-Numbers = {{Ghiringhelli, Giacomo/0000-0003-0867-7748
   Arpaia, Riccardo/0000-0003-4687-2376}},
Funding-Acknowledgement = {{Fondazione CARIPLOFondazione Cariplo; Regione Lombardia under project
   ``ERC-P-ReXS{''} {[}2016-0790]; MIURMinistry of Education, Universities
   and Research (MIUR) {[}2017Z8TS5B]; Narodowe Centrum Nauki (NCN, Poland)
   {[}2016/22/E/ST3/00560, 2016/23/B/ST3/00839]; Center for Integrated
   Quantum Science and Technology (IQST); Swedish Research Council
   (VR)Swedish Research Council {[}2017-00382]}},
Funding-Text = {{We thank Daniel Chrastina for the support with the XRD characterization
   of the samples. RIXS measurements were performed at the beam line ID32
   of the European Synchrotron Radiation Facility (ESRF) with the ERIXS
   spectrometer. R.F, M.M.S. and G.G. acknowledge support by Fondazione
   CARIPLO and Regione Lombardia under project ``ERC-P-ReXS{''} No.
   2016-0790 and by MIUR under project PRIN2017 ``Quantum-2D{''} ID
   2017Z8TS5B. K.W. kindly acknowledges the support by the Narodowe Centrum
   Nauki (NCN, Poland) under Projects Nos. 2016/22/E/ST3/00560 and
   2016/23/B/ST3/00839. M.D. acknowledges support via the Center for
   Integrated Quantum Science and Technology (IQST). R.A. was supported by
   the Swedish Research Council (VR) under the project ``Evolution of
   nanoscale charge order in superconducting YBCO nanostructures
   (2017-00382).{''}}},
Number-of-Cited-References = {{51}},
Times-Cited = {{2}},
Usage-Count-Last-180-days = {{10}},
Usage-Count-Since-2013 = {{14}},
Journal-ISO = {{Phys. Rev. B}},
Doc-Delivery-Number = {{LL7JE}},
Unique-ID = {{ISI:000531732200003}},
DA = {{2020-12-22}},
}