Fig. 1. (a) Schematic of the C-QED system coupled to an auxiliary cavity, and the two cavities coupled to each other via the photon-hopping interaction; (b) two energy levels of a QD coupled to a single-cavity mode and two optical fields; (c) and (d) are the energy level transitions with an entangled state |ntot⟩ (na and nc represent the number state of the photon mode of cavity a and cavity c; ntot=na+nc is the total photon number of the two cavities).

Fig. 2. (a)–(c) Probe absorption spectra of the probe field as a function of probe detuning Δs at Δp=0 under three conditions, i.e., weak coupling, intermediate coupling, and strong coupling regimes. The parameters used are Γ1=5.2  MHz, κa=κc=8.0  MHz, Ωpu2=1.0 (MHz)2, Δa=0, Δc=0.

Fig. 3. Probe absorption spectra as a function of cavity-cavity coupling strength J in the weak coupling regime (g=2.0  MHz). The other parameters are the same as in Fig. 2.

Fig. 4. Probe absorption spectra as a function of cavity-cavity coupling strength J in the intermediate coupling regime (g=6.0  MHz). The other parameters are the same as in Fig. 2.

Fig. 5. Probe absorption spectra as a function of cavity-cavity coupling strength J in the strong coupling regime (g=30  MHz). The other parameters are the same as in Fig. 2.

Fig. 6. Probe absorption spectra as a function of the pump frequency detuning Δp in the strong coupling regime (g=30  MHz). J=2.0κa, Ωp2=20 (MHz)2, and the other parameters are the same as in Fig. 2.