Optimizing the RVB state on a triangular lattice: Presence of the long-range order

TL;DR

This paper develops a Schwinger-boson approach to optimize the RVB state on a triangular lattice, demonstrating the presence of long-range order and achieving results consistent with exact diagonalization.

Contribution

It introduces a self-consistent optimization method for the RVB wavefunction that captures long-range order on a triangular lattice.

Findings

Optimized RVB state exhibits long-range three-sublattice order.

Monte Carlo energies match exact diagonalization results.

The approach effectively captures magnetic correlations.

Abstract

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 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 wavefunction possesses a long-range three-sublattice order.