Figure 3
Negativity volume \({\mathscr{V}}\) of the Wigner function W given in Eq. (26) (blue solid curve) for the state \(|{\rm{\Psi }}\rangle \) in Eq. (23), negativity volume \({\mathscr{V}}\) of the Wigner function \({W}_{q}[{\hat{\rho }}^{q}]\) of the reduced qubit state \({\hat{\rho }}^{q}\) (red dashed curve), entanglement negativity \({\mathscr{N}}\) of the state \(|{\rm{\Psi }}\rangle \) (green dash-dotted curve) as a function of |α|. At \(|\alpha |=0\) the negativity volume of the Wigner function \(V={V}_{cr}\mathrm{=1/}\sqrt{3}-\mathrm{1/2}\).
