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Spin wave dispersion softening in the ferromagnetic Kondo lattice model for manganites

F. Mancini·N. B. Perkins·N. M. Plakida
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Abstract

Spin dynamics is calculated in the ferromagnetic (FM) state of the generalized Kondo lattice model taking into account strong on-site correlations between e_g electrons and antiferromagnetic (AFM) exchange among t_{2g} spins. Our study suggests that competing FM double-exchange and AFM super-exchange interaction lead to a rather nontrivial spin-wave spectrum. While spin excitations have a conventional Dq^2 spectrum in the long-wavelength limit, there is a strong deviation from the spin-wave spectrum of the isotropic Heisenberg model close to the zone boundary. The relevance of our results to the experimental data are discussed.

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F. Mancini, N. B. Perkins, N. M. Plakida. 2000-11-28. Spin wave dispersion softening in the ferromagnetic Kondo lattice model for manganites. https://doi.org/10.1016/s0375-9601(01)00321-8

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