ON POSITIVE MAPS; PPT STATES AND ENTANGLEMENT

摘要

In Quantum Computing a characterization of states with positive partial transposition (PPT states) is of paramount importance (see ~(11)and also~6). In~(19) it was pointed out that there are strong relations between large class of positive maps (decomposable maps) and the subset of all PPT states. Recently, employing relations between certain positive maps and states, the full description of PPT states was obtained in~(15), see also~(25). The aim of this note, based on~(15), is to review characterization of PPT states with the special emphasis put on the structure of positive maps and tensor products of certain algebras.