title: Spin liquid phases for spin-1 systems on the triangular lattice.
abstract: Motivated by recent experiments on material Ba3NiSb2O9, we propose two novel spin liquid phases (A and B) for spin-1 systems on a triangular lattice. At the mean field level, both spin liquid phases have gapless fermionic spinon excitations with quadratic band touching; thus, in both phases the spin susceptibility and γ=C(v)/T saturate to a constant at zero temperature, which are consistent with the experimental results on Ba3NiSb2O9. On the lattice scale, these spin liquid phases have Sp(4)~SO(5) gauge fluctuation, while in the long wavelength limit this Sp(4) gauge symmetry is broken down to U(1)×Z(2) in the type A spin liquid phase, and broken down to Z(4) in the type B phase. We also demonstrate that the A phase is the parent state of the ferroquadrupole state, nematic state, and the noncollinear spin density wave state.
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106, USA.
authors.forename: Cenke
authors.initials: C
authors.lastname: Xu
authors.forename: Fa
authors.initials: F
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Qi
authors.forename: Leon
authors.initials: L
authors.lastname: Balents
authors.forename: Matthew P A
authors.initials: MP
authors.lastname: Fisher