Two-magnon Raman scattering in a Mott-Hubbard antiferromagnet
- Department of Physics, Indian Institute of Technology, Kanpur 208016 (India)
A perturbation-theoretic diagrammatic scheme is developed for systematically studying the two-magnon Raman scattering in a Mott-Hubbard antiferromagnet. The fermionic structure of the magnon interaction vertex is obtained at order-1/{ital N} level in an inverse-degeneracy expansion, and the relevant two-magnon propagator is obtained by incorporating magnon interactions at a ladder-sum level. Evaluation of the magnon interaction vertex in the large-{ital U} limit yields a nearest-neighbor instantaneous interaction with interaction energy {minus}{ital J}. Application of this approach to the intermediate-{ital U} regime, which is of relevance for cuprate antiferromagnets, is also discussed. Incorporating the zero-temperature magnon damping, which is estimated in terms of quantum spin fluctuations, the two-magnon Raman scattering intensity is evaluated and compared with experiments on La{sub 2}CuO{sub 4}. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 383247
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 54, Issue 9; Other Information: PBD: Sep 1996
- Country of Publication:
- United States
- Language:
- English
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