Impurity spin dynamics in 2D antiferromagnets and superconductors
arXiv:cond-mat/0002316 · doi:10.1016/S0921-4534(00)00503-7
Abstract
We discuss the universal theory of localized impurities in the paramagnetic state of 2D antiferromagnets where the spin gap is assumed to be significantly smaller than a typical exchange energy. We study the impurity spin susceptibility near the host quantum transition from a gapped paramagnet to a Neel state, and we compute the impurity-induced damping of the spin-1 mode of the gapped antiferromagnet. Under suitable conditions our results apply also to d-wave superconductors.
2 pages, 1 fig. Proceedings of the M2S-HTSC-VI conference, Houston 2000, submitted to Physica C. More details can be found in cond-mat/9912020