Statistics of the excitations of the resonating-valence-bond state

Abstract
By extending recent proposals for choosing the phases in resonating-valence-bond ground states to the case of excited states, we show for these wave functions that the hole excitations are charged, spinless fermions and the spin excitations are neutral, spin-(1/2 bosons. We also show that for a system with periodic boundary conditions, all states are at least fourfold degenerate.