Derzhko, OlegOlegDerzhkoHonecker, AndreasAndreasHoneckerRichter, JohannesJohannesRichter2018-11-072018-11-072009https://resolver.sub.uni-goettingen.de/purl?gro-2/17539We study the repulsive Hubbard model both analytically and numerically on a family of highly frustrated lattices which have one-electron states localized on isolated trapping cells. We construct and count exact many-electron ground states for a wide range of electron densities and obtain closed-form expressions for the low-temperature thermodynamic quantities which are universal for all lattices of the family. Furthermore, we find that saturated ferromagnetism is obtained only for sufficiently high electron densities and large Hubbard repulsion U while there is no finite average moment in the ground states at lower densities.journal_article10.1103/PhysRevB.79.054403000263815400044