2D multipartite valence bond states in quantum anti-ferromagnets

A quantum anti-ferromagnetic spin-1 model is characterised on a 2D lattice with the following requirements: (i) The Hamiltonian is made out of nearest neighbour interactions. (ii) It is homogeneous, translational and rotational invariant. (iii) The ground state is a real singlet state of SU(2) (non-chiral). (iv) It has a local spin-1 representation. Along the way to characterise the system, connections with classical statistical mechanics and integrable models are explored. Finally, the relevance of the model in the physics of low dimensional anti-ferromagnetic Mott-Hubbard insulators is discussed. (C) 2008 Elsevier Inc. All rights reserved.