The notion of Z(2) topological order in two-dimensional resonating-valence-bond systems is reviewed. Using quantum dimer models as an example, I discuss general properties of the topological order and the resulting vortex-like excitations (visons). Some co ...
Amer Inst Physics, 2 Huntington Quadrangle, Ste 1No1 D, Melville, Ny 11747-4501 Usa2009