2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/106966We studied quantum depletion in a gaseous Bose-Einstein condensate. An optical lattice enhanced the atomic interactions and modified the dispersion relation resulting in strong quantum depletion. The depleted fraction was directly observed as a diffuse background in the time-of-flight images. Bogoliubov theory provided a semi-quantitative description for our observations of depleted fractions in excess of 50%.Replaced with accepted version in PRLOther Condensed Mattertext