Resonating valence bond wave functions for strongly frustrated spin systems

The resonating-valence-bond (RVB) theory for two-dimensional quantum antiferromagnets is shown to be the correct paradigm for large enough quantum frustration. This scenario, proposed a long time ago but never confirmed by rnicroscopic calculations, is strongly supported by a new type of variational wave function, which is extremely close to the exact ground state of the J(1) - J(2) Heisenberg model for 0.4 less than or similar to J(2)/J(1) less than or similar to 0.5. This wave function is proposed to represent the generic spin-half RVB ground state in spin liquids.