Universal properties of highly frustrated quantum magnets in strong magnetic fields

The purpose of the present paper is twofold. On the one hand, we review some recent studies on the low-temperature strong-field thermodynamic properties of frustrated quantum spin antiferromagnets which admit the so-called localized-magnon eigenstates. On the other hand, we provide some complementary new results. We focus on the linear independence of the localized-magnon states, the estimation of their degeneracy with the help of auxiliary classical lattice-gas models, and the analysis of the contribution of these states to thermodynamics. (c) 2007 American Institute of Physics.