2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/100483We present a controlled method for computing the exchange coupling in strongly correlated one-dimensional electron systems. It is based on the asymptotically exact relation between the exchange constant and the pair-correlation function of spinless electrons. Explicit results are obtained for thin quantum rings with realistic Coulomb interactions, by calculating this function via a many-body instanton approach.7 pages, 2 figures. Changes in the text and figures to improve readability; added referencesStrongly Correlated Electronstext