Entanglement of two Jaynes-Cummings atoms in single-excitation space

Ya Yang,Yan Liu,Jing Lu,Lan Zhou

Figure 2. Figures (a), (c), and (e) show the evolution of the function ${Q}_{{AB}}\left(t\right)$ for the concurrence of two atoms over time when the initial state is $\left|{\psi }_{{AB}}\left(0\right)\right\rangle $, and (b), (d), and (f) express ${Q}_{{ab}}\left(t\right)$ when the initial state is $\left|{\psi }_{{ab}}\left(0\right)\right\rangle $. The ratio of the coupling strengths takes a value of $\tfrac{{g}_{A}}{{g}_{B}}=1$ in subgraphs (a) and (b), $\tfrac{{g}_{A}}{{g}_{B}}=\sqrt{2}$ in subgraphs (c) and (d), and $\tfrac{{g}_{A}}{{g}_{B}}=2$ in subgraphs (e) and (f). In both subgraphs, the gray-blue solid lines represent the initial-state parameter $\theta =\tfrac{\pi }{4}$, the red dashed lines represent $\theta =\tfrac{\pi }{6}$, and the blue dotted lines represent $\theta =\tfrac{\pi }{12}$.