Entanglement, fractional magnetization and long-range interactions
  Based on the theory of Matrix Product States, we give precise statements and complete analytical proofs of the following claim: a large fractionalization in the magnetization or the need of long-range interactions imply large entanglement in the state of a quantum spin chain. 
Andrea Cadarso, Mikel Sanz, Michael M. Wolf, J. Ignacio Cirac, David   Perez-Garcia
quant-ph cond-mat.str-el math-ph math.MP