Gs. Tian, A SUFFICIENT CONDITION FOR 2 LONG-RANGE ORDERS COEXISTING IN A LATTICE MANY-BODY SYSTEM, Journal of physics. A, mathematical and general, 30(3), 1997, pp. 841-848
In this paper, we prove a sufficient condition for two long-range orde
rs being either present or absent simultaneously in the absolute groun
d state of a lattice many-body boson or fermion model. As an applicati
on of this theorem, we give a simplified proof on the coexistence of t
he resonating valence bond (RVB) long-range order and the on-site-pair
ing long-range order in the ground state of the Hubbard model.