Abstract
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 yield a reliable estimate of the superexchange parameter J=135±4 meV using a classical spin-1/2 two-dimensional 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. Due 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.
Original language | English |
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Article number | 155110 |
Journal | Physical Review B |
Volume | 95 |
Issue number | 15 |
DOIs | |
State | Published - Apr 7 2017 |
Externally published | Yes |