2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/151834Theoretical foundations of the problem of quantum spin tunneling in magnetic nanostructures are presented. Several model problems are considered in detail, including recent new results on tunneling in antiferromagnetic nanoparticles and topologically nontrivial magnetic structures in systems with reduced dimension.31 page, 4 embedded ps-figures, uses crckapb.sty and psfig.sty (to be published in the proceedings of NATO ASI "Frontiers in Magnetism of Reduced Dimension Systems", Partenit, Crimea/Ukraine, May 25 - June 3, 1997)Mesoscale and Nanoscale PhysicsStrongly Correlated Electronstext