Discussion of a spin-cluster model for the low temperature phase of NaV_2O_5
arXiv:cond-mat/0008172 · doi:10.1103/PhysRevB.62.R14613
Abstract
We discuss magnetic excitations of a spin-cluster model which has been suggested to describe the low temperature phase of alpha'-NaV_2O_5. This model fulfills all symmetry criteria proposed by recent x-ray investigations. We find that this model is not able to describe the occurence of two well separated magnon lines perpendicular to the ladder direction as observed in INS experiments. We suggest further experimental analysis to generally distinguish between models with double reflection or inversion symmetry.
4 pages, 4 figures, added a calculation of level repulsion