1212.6035 (Hosho Katsura et al.)

Ground States of the Spin-1 Bose-Hubbard Model    [PDF]

Hosho Katsura, Hal Tasaki

We prove basic theorems about the ground states of the S=1 Bose-Hubbard model. The results are quite universal and depend only on the coefficient U_2 of the spin-dependent interaction. We show that the ground state exhibits saturated ferromagnetism if U_2<0, is spin-singlet if U_2>0, and exhibits "SU(3)-ferromagnetism" if U_2=0, and completely determine the degeneracy in each region.

View original: http://arxiv.org/abs/1212.6035