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

TL;DR

This study investigates the zero-temperature magnetic phases of the spin-1/2 Heisenberg antiferromagnet on a simple cubic lattice with competing interactions, revealing a first-order phase transition and the effects of spin-wave interactions.

Contribution

It applies non-linear spin wave theory to identify phase boundaries and the impact of quartic corrections on magnetization, aligning well with Monte Carlo results.

Findings

Identifies two magnetic phases: Neel and collinear antiferromagnetic.

Finds a first-order phase transition at J2/cJ1=0.28.

Shows quartic corrections eliminate the intermediate paramagnetic phase.

Abstract

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 Neel 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, pc = 0.28. Our results for the value of pc are in excellent agreement with results from Monte-Carlo simulations and variational spin wave theory. 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.