Figure 5

Dependence on the damping coefficient γt of the 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 \(\kappa =0\). The critical NV \({{\mathscr{V}}}_{cr}\) is shown by red dotted line.