  In this paper we introduce a nonextensive quantum information theoretic
measure which may be defined between any arbitrary number of density matrices,
and we analyze its fundamental properties in the spectral graph-theoretic
framework. Unlike other entropic measures, the proposed quantum divergence is
symmetric, matrix-convex, theoretically upper-bounded, and has the advantage of
being generalizable to any arbitrary number of density matrices, with a
possibility of assigning weights to these densities.
