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Spin Excitations in La2CuO4: Consistent Description by Inclusion of Ring-Exchange

A. A. Katanin·A. P. Kampf
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Abstract

We consider the square lattice Heisenberg antiferromagnet with plaquette ring exchange and a finite interlayer coupling leading to a consistent description of the spin-wave excitation spectrum in La2CuO4. The values of the in-plane exchange parameters, including ring-exchange J_{\Box}, are obtained consistently by an accurate fit to the experimentally observed in-plane spin-wave dispersion, while the out-of-plane exchange interaction is found from the temperature dependence of the sublattice magnetization at low temperatures. The fitted exchange interactions J=151.9 meV and J_{\Box}=0.24 J give values for the spin stiffness and the Neel temperature in excellent agreement with the experimental data.

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A. A. Katanin, A. P. Kampf. 2001-11-28. Spin Excitations in La2CuO4: Consistent Description by Inclusion of Ring-Exchange. https://doi.org/10.1103/physrevb.66.100403

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