Three body interaction effects on the phase diagram of spinor bosons

Abstract

We include a three body density interaction in the Bose Hubbard model and study its effects on the phase diagram for spinor (S = 1) bosons on an optical lattice via a mean field theory. The Mott insulating (MI) phases are noted to stabilize, in the sense that the MI phases extend to larger values of the system parameters alongwith widening of the particle-hole excitation spectrum as the three body interaction term is included for both the polar (spin dependent interaction being positive) and the ferromagnetic (spin dependent interaction being negative) cases. Another remarkable feature emerges as the phase diagram corresponding to the ferromagnetic case becomes distinct from that of its spinless variant, which in the absence of the three body term is indistinguishable from that of the scalar particles. A strong coupling perturbation theory is employed to provide analytical support to the above results.