2000/06/30 by Marek Kus, Karol Zyczkowski · 2 citations
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physreva.63.032307
published as Phys. Rev A 63 032307-13 (2001) · 16 latex pages, 4 figures in epsf, minor corrections, references updated, to appear in Phys. Rev. A
arxiv created 2000/12/21 · arxiv updated 2009/12/01
Geometric properties of the set of quantum entangled states are investigated. We propose an explicit method to compute the dimension of local orbits for any mixed state of the general K x M problem and characterize the set of effectively different states (which cannot be related by local transformations). Thus we generalize earlier results obtained for the simplest 2 x 2 system, which lead to a stratification of the 6D set of N=4 pure states. We define the concept of absolutely separable states, for which all globally equivalent states are separable.