Equivalence between two-mode spin squeezed states and pure entangled   states with equal spin
  We prove that a pure entangled state of two subsystems with equal spin is equivalent to a two-mode spin-squeezed state under local operations except for a set of bipartite states with measure zero, and we provide a counterexample to the generalization of this result to two subsystems of unequal spin. 
Dominic W. Berry and Barry C. Sanders