Mobile orbitons in Ca2CuO3 : Crucial role of Hund's exchange
| Autor: | Lucio Braicovich, Riccardo Arpaia, D. Di Castro, Matteo A. C. Rossi, Krzysztof Wohlfeld, Giacomo Claudio Ghiringhelli, R. Fumagalli, M. Moretti Sala, J. Heverhagen, N. B. Brookes, D. Betto, Maria Daghofer |
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| Rok vydání: | 2020 |
| Předmět: |
Physics
Condensed matter physics Orbiton Scattering Continuum (design consultancy) 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Spinon Spectral line 0103 physical sciences Antiferromagnetism Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology |
| Zdroj: | Physical Review B. 101 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.101.205117 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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