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The tripartite separability of density matrices of graphs

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 نشر من قبل Zhi-Xi Wang
 تاريخ النشر 2007
  مجال البحث فيزياء
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The density matrix of a graph is the combinatorial laplacian matrix of a graph normalized to have unit trace. In this paper we generalize the entanglement properties of mixed density matrices from combinatorial laplacian matrices of graphs discussed in Braunstein {it et al.} Annals of Combinatorics, {bf 10}(2006)291 to tripartite states. Then we proved that the degree condition defined in Braunstein {it et al.} Phys. Rev. A {bf 73}, (2006)012320 is sufficient and necessary for the tripartite separability of the density matrix of a nearest point graph.



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