Phase diagram of spin-12 quantum Heisenberg J1–J2J1–J2 antiferromagnet on the body-centered-cubic lattice in random phase approximation

• RPA method applied on J1–J2 Heisenberg antiferromagnet on a bcc lattice.
• Magnon spectrum and thermodynamic properties are determined.
• Agreement with previous results at both high and low temperatures.

Magnetic properties of spin 12J1–J2 Heisenberg antiferromagnet on the body centered cubic lattice are investigated. By using two-time temperature Green's functions, sublattice magnetization and critical temperature depending on the frustration ratio p=J2/J1p=J2/J1 are obtained in both stripe and Néel phases. The analysis of ground state sublattice magnetization and phase diagram indicates the critical end point at J2/J1=0.714J2/J1=0.714, in agreement with previous studies.