We perform some systematic numerical search for Schwinger boson mean field states on square and triangular lattice clusters. We look for possible inhomogeneous ground states as well as low-energy excited saddle points. The spectrum of the Hessian is also computed for each solution. On the square lattice we find gapless U(1) gauge modes in the non-magnetic phase. In the Z_2 liquid phase of the triangular lattice we identify the topological degeneracy as well as vison states.
Categories: cond-mat.str-el