2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/16030Calculations of nuclear spin-lattice relaxation rates are carried out by means of exact diagonalization on small (2 x 6) antiferromagnetic Heisenberg ladders, using the simplest forms permitted by symmetry for the hyperfine couplings for the three nuclear sites in Cu2O3 ladders. Several values of the rung/chain exchange ratio have been considered. Comparisons with experimental results, field theoretic calculations, and the Gaussian approximation highlight some open problems.13 pages (including 4 figures) preprint format, uses Revtex4 (beta 3)Strongly Correlated Electronstext