Resonant inelastic X-ray scattering study of spin-wave excitations in the cuprate parent compound Ca 2 CuO 2 Cl 2

B. W Lebert (1, 2) , M. P M Dean (3) , A. Nicolaou (2) , J. Pelliciari (4) , M. Dantz (4) , T. Schmitt (4) , R. Yu (5) , M Azuma (5) , J.-P. Castellan (6, 7) , H. Miao (3) , A. Gauzzi (1) , B. Baptiste (1) , M. d'Astuto (1)

1 IMPMC - Institut de minéralogie, de physique des matériaux et de cosmochimie
2 SSOLEIL - Synchrotron SOLEIL
3 Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory
4 SLS-PSI - The Swiss Light Source (SLS)
5 TITECH - Tokyo Institute of Technology [Tokyo]
6 KIT - Karlsruhe Institute of Technology
7 LLB - UMR 12 - Laboratoire Léon Brillouin

By means of resonant inelastic x-ray scattering at the Cu L3 edge, we measured the spin wave dispersion along 100 and 110 in the undoped cuprate Ca2CuO2Cl2. The data yields a reliable estimate of the superexchange parameter J = 135 ± 4 meV using a classical spin-1/2 2D Heisenberg model with nearest-neighbor interactions and including quantum fluctuations. Including further exchange interactions increases the estimate to J = 141 meV. The 40 meV dispersion between the magnetic Brillouin zone boundary points (1/2, 0) and (1/4, 1/4) indicates that next-nearest neighbor interactions in this compound are intermediate between the values found in La2CuO4 and Sr2CuO2Cl2. Owing to the low-Z elements composing Ca2CuO2Cl2, the present results may enable a reliable comparison with the predictions of quantum many-body calculations, which would improve our understanding of the role of magnetic excitations and of electronic correlations in cuprates.

Mots clés: Superconductivity; hole-doped cuprate; inelastic X-ray scattering

Domaines: Electrons fortement corrélés [cond-mat.str-el]; Supraconductivité [cond-mat.supr-con]

B. W Lebert, M. P M Dean, A. Nicolaou, J. Pelliciari, M. Dantz, et al.. Resonant inelastic X-ray scattering study of spin-wave excitations in the cuprate parent compound Ca 2 CuO 2 Cl 2. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2017, 95 (15), pp.155110. ⟨10.1103/PhysRevB.95.155110⟩. ⟨hal-01388544v4⟩