Figure 1

The Q function \(\langle \beta |\hat{\rho }|\beta \rangle /\pi \) of the reduced density matrix \(\hat{\rho }\) of the cavity in the ground state \(|G\rangle \), where \(\beta =X+iP\). Here \({\omega }_{{\rm{q}}}=2\pi \times 0.299\,{\rm{GHz}}\), \(g=2\pi \times 4.920\,{\rm{GHz}}\), \({\omega }_{{\rm{r}}}=2\pi \times 6.336\,{\rm{GHz}}\).