The Laplacian of a Graph as a Density Matrix: A Basic Combinatorial Approach to Separability of Mixed States

Authors: Samuel L. Braunstein, Sibasish Ghosh, Simone Severini - Annals of Combinatorics 2004 cited by 135

We study entanglement properties of mixed density matrices obtained from combinatorial laplacian matrices of graphs. We observe that some classes of graphs give arise to entangled (separable) states independently of their labelings.