Non--Heisenberg Spin Dynamics of Double-Exchange Ferromagnets with Coulomb Repulsion

Abstract

With a variational three--body calculation we study the role of the interplay between the onsite Coulomb, Hund's rule, and superexchange interactions on the spinwave excitation spectrum of itinerant ferromagnets. We show that correlations between a Fermi sea electron--hole pair and a magnon result in a very pronounced zone boundary softening and strong deviations from the Heisenberg spinwave dispersion. We show that this spin dynamics depends sensitively on the Coulomb and exchange interactions and discuss its possible relevance to experiments in the manganites.

arXiv comment4 pages, 4 figures, published in Physical Review B as rapid communications

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Cited by in corpus (13)

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• Magnetization Relaxation and Collective Spin Excitations in Correlated Double--Exchange Ferromagnets
• Spin-charge coupling in a band ferromagnet: magnon-energy reduction, anomalous softening, and damping
• Correlating Quasi-Electron Relaxation with Quantum Femtosecond Magnetism in the Order Parameter Dynamics of Insulating Manganites
• Dynamics of Phase Separated States in the Double Exchange Model
• Fermionic representation for the ferromagnetic Kondo lattice model -- diagrammatic study of spin-charge coupling effects on magnon excitations
• Interacting spin waves in the ferromagnetic Kondo lattice model
• Strongly anharmonic collective modes in a coupled electron-phonon-spin problem
• Spin-charge and spin-orbital coupling effects on spin dynamics in ferromagnetic manganites
• Magnon self energy in the correlated ferromagnetic Kondo lattice model: spin-charge coupling effects on magnon excitations in manganites