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

Ya Yang,Yan Liu,Jing Lu,Lan Zhou

Figure 3. A comparison of the atomic concurrence, ${{\mathbb{C}}}^{{AB}}$, with two different kinds of initial state. The gray-blue solid lines shows the evolution process of the concurrence for the initial state $\left|{\psi }_{{AB}}\left(0\right)\right\rangle $, while the red dashed lines depict the case for the initial state $\left|{\psi }_{{ab}}\left(0\right)\right\rangle $. The initial-state parameter, θ, is fixed at $\tfrac{\pi }{6}$ in all subgraphs. In subgraphs (a) and (c), the ratios of the coupling strengths $\tfrac{{g}_{A}}{{g}_{B}}$ take values of 2 and 3, respectively. Subgraphs (b) and (d) are a comparison between ${Q}_{{ab}}\left({gt}\right)$ and ${Q}_{{AB}}\left({gt}\right)$ after shifting the phase to the left by $\tfrac{\pi }{2}$.