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arXiv · 1610.08383

Resonant inelastic X-ray scattering study of spin-wave excitations in the cuprate parent compound Ca$_{2}$CuO$_2$Cl$_2$

B. W. Lebert·M. P. M. Dean·A. Nicolaou·J. Pelliciari·M. Dantz·T. Schmitt·R. Yu·M. Azuma·J-P. Castellan·H. Miao·A. Gauzzi·B. Baptiste·M. d'Astuto
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Abstract

By means of resonant inelastic x-ray scattering at the Cu L$_3$ edge, we measured the spin wave dispersion along $\langle$100$\rangle$ and $\langle$110$\rangle$ in the undoped cuprate Ca$_2$CuO$_2$Cl$_2$. The data yields a reliable estimate of the superexchange parameter $J$ = 135 $\pm$ 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 La$_{2}$CuO$_4$ and Sr$_2$CuO$_2$Cl$_2$. Owing to the low-$Z$ elements composing Ca$_2$CuO$_2$Cl$_2$, 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.

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B. W. Lebert, M. P. M. Dean, A. Nicolaou, J. Pelliciari, M. Dantz, T. Schmitt, R. Yu, M. Azuma, J-P. Castellan, H. Miao, A. Gauzzi, B. Baptiste, M. d'Astuto. 2016-10-26. Resonant inelastic X-ray scattering study of spin-wave excitations in the cuprate parent compound Ca$_{2}$CuO$_2$Cl$_2$. https://doi.org/10.1103/physrevb.95.155110

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