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Spin-wave excitation spectra and spectral weights in square lattice antiferromagnets

Rajiv R. P. Singh·Martin P. Gelfand
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Abstract

Using a recently developed method for calculating series expansions of the excitation spectra of quantum lattice models, we obtain the spin-wave spectra for square lattice, $S=1/2$ Heisenberg-Ising antiferromagnets. The calculated spin-wave spectrum for the Heisenberg model is close to but noticeably different from a uniformly renormalized classical (large-$S$) spectrum with the renormalization for the spin-wave velocity of approximately $1.18$. The relative weights of the single-magnon and multi-magnon contributions to neutron scattering spectra are obtained for wavevectors throughout the Brillouin zone.

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Rajiv R. P. Singh, Martin P. Gelfand. 1995-09-13. Spin-wave excitation spectra and spectral weights in square lattice antiferromagnets. https://doi.org/10.1103/physrevb.52.r15695

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