2001/11/28 by A. A. Katanin, A. P. Kampf · 1 citation
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.66.100403
published as Phys. Rev. B 66, 100403(R) (2002) · 4 pages, 1 figure, RevTex
arxiv created 2001/11/28 · arxiv updated 2009/11/30
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.