Figure 4

Dependence on the damping coefficient \(\kappa t\) of negativity volume \({\mathscr{V}}\) of the Wigner function W (blue solid curve), and entanglement negativity \({\mathscr{N}}\) of the state \(\hat{\rho }\) (green dash-dotted curve), assuming α = 1, and γ = 0. The critical NV \({{\mathscr{V}}}_{cr}\) is shown by red dotted line.