2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/148678The two-dimensional quantum ferromagnet filled with a liquid of skyrmions is studied theoretically in the context of the quantum Hall effect near electronic filling factor $ν= 1$. A cross-over between the classical ferromagnetic phase at $ν=1$ and a classical paramagnetic phase at $ν\neq 1$ is obtained, which is consistent with recent Knight-shift measurements. A new collective mode associated with the skyrmion liquid that is of the cyclotron type is also identified.10 pgs PLAIN TeX, 2 ps figs, to appear in Europhysics LettersMesoscale and Nanoscale Physicstext