We present a Schwinger boson approach for the RVB state of the spin-1/2 Heisenberg antiferromagnet on a triangular lattice. It is shown that a Gutzwiller projection of the mean field state that includes both antiferromagnetic and ferromagnetic decouplings leads to optimizing the RVB pair amplitudes within a self-consistent approximation. The resulting state yields, by Monte Carlo simulations, energies and spin-spin correlations in excellent agreement with the exact diagonalization result on finite lattices (up to 36 sites). We conclude that the optimized RVB wave function possesses a long range three-sublattice order.
Exact diagonalization and cluster mean-field study of triangular-lattice XXZ antiferromagnets near saturation
