Unraveling higher-order corrections in the spin dynamics of RIXS spectra
| Autor: | Kumar, Umesh, Nag, Abhishek, Li, Jiemin, Robarts, H. C., Walters, A. C., García-Fernández, Mirian, Saint-Martin, R., Revcolevschi, A., Schlappa, Justine, Schmitt, Thorsten, Johnston, Steve, Zhou, Ke-Jin |
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| Rok vydání: | 2021 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.106.L060406 |
| Popis: | Resonant inelastic x-ray scattering (RIXS) is an evolving tool for investigating spin dynamics of strongly correlated materials, which complements inelastic neutron scattering. Both techniques have found that non-spin-conserving (NSC) excitations in quasi-1D isotropic quantum antiferromagnets are confined to the two-spinon phase space. Outside this phase space, only spin-conserving (SC) four-spinon excitations have been detected using O $K$-edge RIXS. Here, we investigate SrCuO$_2$ and find four-spinon excitations outside the two-spinon phase space at both O $K$- and Cu $L_3$-edges. Using the Kramers-Heisenberg formalism, we demonstrate that the four-spinon excitations arise from both SC and NSC processes at Cu $L_3$-edge. We show that these new excitations only appear in the second-order terms of the ultra-fast core-hole lifetime expansion and arise from long-range spin fluctuations. These results thus open a new window to the spin dynamics of quantum magnets. Comment: 10 pages, 4+3 figures |
| Databáze: | arXiv |
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