Spin-1/2 J1-J2 model on the body-centered cubic lattice

TL;DR

This study investigates the effects of frustration and quantum fluctuations on the magnetic phases of the spin-1/2 J1-J2 Heisenberg model on a body-centered cubic lattice, revealing a first-order transition without a disordered phase.

Contribution

It provides the first detailed analysis of the J1-J2 model on the bcc lattice using ED and LSWT, showing a direct transition between magnetic phases without a quantum disordered state.

Findings

No quantum disordered phase for strong frustration on bcc lattice

First order transition at J2/J1 ≈ 0.7 from Neel to collinear phase

Consistent results from ED and LSWT methods

Abstract

Using exact diagonalization (ED) and linear spin wave theory (LSWT) we study the influence of frustration and quantum fluctuations on the magnetic ordering in the ground state of the spin-1/2 J1-J2 Heisenberg antiferromagnet (J1-J2 model) on the body-centered cubic (bcc) lattice. Contrary to the J1-J2 model on the square lattice, we find for the bcc lattice that frustration and quantum fluctuations do not lead to a quantum disordered phase for strong frustration. The results of both approaches (ED, LSWT) suggest a first order transition at J2/J1 $\approx$ 0.7 from the two-sublattice Neel phase at low J2 to a collinear phase at large J2.