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arXiv · 1004.2441

Measurement of magnetic excitations in the two-dimensional antiferromagnetic Sr2CuO2Cl2 insulator using resonant x-ray scattering:Evidence for extended interactions

M. Guarise·B. Dalla Piazza·M. Moretti Sala·G. Ghiringhelli·L. Braicovich·H. Berger·J. N. Hancock·D. van der Marel·T. Schmitt·V. N. Strocov·L. J. P. Ament·J. van den Brink·P. -H. Lin·P. Xu·H. M. Rønnow·M. Grioni
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Abstract

Using high-resolution resonant inelastic x-ray scattering (RIXS), we performed a momentum-resolved study of magnetic excitations in the model spin-1/2 2D antiferromagnetic insulator Sr_2CuCl_2O_2. We identify both a single-spin-wave feature and a multi-magnon continuum, and show that the X-ray polarization can be used to distinguish these two contributions in the cross-section. The spin-waves display a large (70 meV) dispersion between the zone-boundary points ($π$,0) and ($π$/2,$π$/2). Employing an extended $t$-$t'$-$t"$-$U$ one-band Hubbard model, we find significant electronic hopping beyond nearest-neighbor Cu ions. We conclude that sizeable extended magnetic interactions are present in \scoc{} and probably important in all undoped cuprates.

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M. Guarise, B. Dalla Piazza, M. Moretti Sala, G. Ghiringhelli, L. Braicovich, H. Berger, J. N. Hancock, D. van der Marel, T. Schmitt, V. N. Strocov, L. J. P. Ament, J. van den Brink, P. -H. Lin, P. Xu, H. M. Rønnow, M. Grioni. 2010-09-06. Measurement of magnetic excitations in the two-dimensional antiferromagnetic Sr2CuO2Cl2 insulator using resonant x-ray scattering:Evidence for extended interactions. https://doi.org/10.1103/physrevlett.105.157006

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