Spin dynamics is calculated in the ferromagnetic (FM) state of the generalized Kondo lattice model taking into account strong on-site correlations between eg electrons and antiferromagnetic (AFM) exchange among t2g 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 Dq2 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.
|Original language||English (US)|
|Number of pages||8|
|Journal||Physics Letters, Section A: General, Atomic and Solid State Physics|
|State||Published - 2001|
Bibliographical noteFunding Information:
We thank G. Khaliullin and G. Jackeli for valuable discussions. N.B.P. wishes to acknowledge partial support by Unità INFM di Salerno. Financial support by INTAS Program, Grants No. 97-90963 and No. 97-11066, are acknowledged by N.B.P. and N.M.P.