Zero temperature phases of the frustrated J₁-J₂ antiferromagnetic spin-1/2 Heisenberg model on a simple cubic lattice

At zero temperature magnetic phases of the quantum spin-1/2 Heisenberg antiferromagnet on a simple cubic lattice with competing first and second neighbor exchanges (J₁ and J₂) is investigated using the non-linear spin wave theory. We find existence of two phases: a two sublattice Néel phase for small J₂ (AF), and a collinear antiferromagnetic phase at large J₂ (CAF). We obtain the sublattice magnetizations and ground state energies for the two phases and find that there exists a first order phase transition from the AF-phase to the CAF-phase at the critical transition point, p_c = 0.56 or J₂/J₁ = 0.28. We also show that the quartic 1/S corrections due spin-wave interactions enhance the sublattice magnetization in both the phases which causes the intermediate paramagnetic phase predicted from linear spin wave theory to disappear.