Erratum: Superradiance in inverted multilevel atomic clouds [Phys. Rev. A 95, 033839 (2017)]

Figure 2

Comparison of the time dependence resulting from Eq. (1) (solid line) and Eq. (11) (dashed line) for clouds of two-level atoms. (a) Photon emission rate per atom, ${\gamma }^{\prime }\equiv \gamma /N$, for clouds where $N=10$, and densities: ${\lambda }_g^3\mathcal{N}=125$ and ${\lambda }_g^3\mathcal{N}\simeq 37$. (b) Excitation probability, $N_e/N$, for clouds where $N=10$, and ${\lambda }_g^3\mathcal{N}\simeq 1000,37,$ and 8. Note that in the figure, the values of ${\lambda }_g^3\mathcal{N}$ are inversely proportional to the slope of $N_e$. (c) $N_e/N$ for $N=10,40$, and 160 two-level atoms using the Dicke model, i.e., $\mathcal{N}\to \infty$ and $H_{ed}=0$. Results are shown for the full calculation obtained using Eq. (1), as well as the approximate Eq. (11). Note that the two calculations scale with $N$ in the same manner.