Laboratoire de Physique Théorique
Toulouse - UMR 5152

The theoretical study of two—dimensional ``spin liquids’’ — quantum magnets which remain disordered at the very lowest temperatures — has mostly been confined to models with competing or frustrated antiferromagnetic (AF) interactions. The resulting ground states typically involve strong singlet bonds between spins, which give rise to a gap in the spin excitation spectrum. None the less, the best characterized experimental realization of a spin liquid is believed to occur in two—dimensional films of solid He, where the interactions between spins are predominantly ferromagnetic (FM), and the resulting state is gapless. Here we consider whether the breakdown of long ranged FM order offers a new route unconventional magnetic ground states in two dimensions, considering in detail the case of the square lattice frustrated ferromagnet.

Talk (PDF Format)