Nonextensive Statistical Mechanics

7.1 Physics 2574.0q relc3.53.02.52.00.000 0.005 1/J 0.010Fig. 7.47 Values of q c relvs. 1/J. These are determined by exploring a number of perturbationsmuch less than δ c . We note that q c rel of the J = 480 QKT is larger than q rel reported in Fig. 7.46.It is unclear why in this instance the value of q rel decreases with increased perturbation strength(from [547]).Fig. 7.48 The physical space of the mixed state considered in the present paper is the tetrahedrondetermined by the four big circles. Every big circle and its three neighboring small circlesdetermine a region (small tetrahedron) where no separability is possible. The four small tetrahedradelimit a central octahedron where the system is separable. The x + y + z = 1plane(dashed)generalizes the x c = 1/3 Peres criterion, and plays the role of a critical surface. The entanglement“order parameter” η ≡ 1/q I is zero inside the central octahedron, and continuously increases whenwe approach the four vertices of the big tetrahedron, where η = 1 (from [549]).