Separability and Entanglement of Identical Bosonic Systems
  We investigate the separability of arbitrary $n$-dimensional multipartite identical bosonic systems. An explicit relation between the dimension and the separability is presented. In particular, for $n=3$, it is shown that the property of PPT (positive partial transpose) and the separability are equivalent for tripartite systems. 
Xiao-Hong Wang, Shao-Ming Fei, Ke Wu