Systematic Study of Magnetic Interactions in Insulating Cuprates
arXiv:cond-mat/9912480 · doi:10.1016/S0921-4534(00)00549-9
Abstract
The magnetic interactions in one-dimensional, two-dimensional (2D) and ladder cuprates are evaluated systematically by using small Cu-O clusters. We find that the superexchange interaction J between nearest neighbor Cu spins strongly depends on Cu-O structure through the Madelung potential, and in 2D and ladder cuprates there is a four-spin interaction Jcyc, with magnitude of 10% of J. We show that Jcyc has a strong influence on the magnetic excitation in the high-energy region of 2D cuprates.
2 pages, 1 figure, with minor corrections, M2S-HTSC-VI conference proceedings