Local description of quantum inseparability
Abstract
We show how to decompose any density matrix of the simplest binary composite systems, whether separable or not, in terms of only product vectors. We determine for all cases the minimal number of product vectors needed for such a decomposition. Separable states correspond to mixing from one to four pure product states. Inseparable states can be described as pseudomixtures of four or five pure product states, and can be made separable by mixing them with one or two pure product states.
 Publication:

Physical Review A
 Pub Date:
 August 1998
 DOI:
 10.1103/PhysRevA.58.826
 arXiv:
 arXiv:quantph/9801024
 Bibcode:
 1998PhRvA..58..826S
 Keywords:

 03.65.Bz;
 42.50.Dv;
 89.70.+c;
 Nonclassical states of the electromagnetic field including entangled photon states;
 quantum state engineering and measurements;
 Information theory and communication theory;
 Quantum Physics
 EPrint:
 5 pages latex