Fermionic representation for the ferromagnetic Kondo lattice model -- diagrammatic study of spin-charge coupling effects on magnon excitations
Abstract
A purely fermionic representation is introduced for the ferromagnetic Kondo lattice model which allows conventional diagrammatic tools to be employed to study correlation effects. Quantum 1/S corrections to magnon excitations are investigated using a systematic inverse-degeneracy expansion scheme which incorporates correlation effects in the form of self-energy and vertex corrections, while explicitly preserving the continuous spin-rotation symmetry. Magnon self-energy is studied in the full range of interaction strength, and shown to result in strong magnon damping and anomalous softening for zone boundary modes, which accounts for several zone-boundary anomalies observed in recent spin-wave measurements of ferromagnetic manganites.
Keywords
Cite
@article{arxiv.0710.2828,
title = {Fermionic representation for the ferromagnetic Kondo lattice model -- diagrammatic study of spin-charge coupling effects on magnon excitations},
author = {Sudhakar Pandey and Subrat Das and Bhaskar Kamble and Saptarshi Ghosh and Dheeraj Singh and Rajyavardhan Ray and Avinash Singh},
journal= {arXiv preprint arXiv:0710.2828},
year = {2009}
}
Comments
16 pages, 9 figures