Parametrically driven hybrid qubit-photon systems: Dissipation-induced quantum entanglement and photon production from vacuum

We consider a dissipative evolution of a parametrically driven qubit-cavity system under the periodic modulation of coupling energy between two subsystems, which leads to the amplification of counter-rotating processes. We reveal a very rich dynamical behavior of this hybrid system. In particular, we find that the energy dissipation in one of the subsystems can enhance quantum effects in another subsystem. For instance, optimal cavity decay assists the stabilization of entanglement and quantum correlations between qubits even in the steady state and the compensation of finite qubit relaxation. On the contrary, energy dissipation in qubit subsystems results in enhanced photon production from vacuum for strong modulation but destroys both quantum concurrence and quantum mutual information between qubits. Our results provide deeper insights to nonstationary cavity quantum electrodynamics in the context of quantum information processing and might be of importance for dissipative quantum state engineering.

Figure 1

Color map for the time evolution of the quantum concurrence between the two qubits at $g_0=0.05\omega$ and different values of parameter $\theta$ at cavity relaxation rate (a) $\kappa =0$ and (b) $0.01\omega$.

Figure 2

Time evolution of quantum concurrence between two qubits at $g=0.05\omega$ for (a) $\theta =0.84$ and (b) $\theta =0.16$ calculated analytically (blue solid lines) using perturbation theory around the (a) Tavis–Cummings and (b) anti-Tavis–Cummings (b) regimes and numerically (red dashed lines).

Figure 3

Color map for the time evolution of the quantum concurrence between the two qubits at $g=0.05$ and different values of parameter $\theta$ at (a) $\kappa =0.005\omega$, $\gamma =0.02\omega$ and (b) $\kappa =0.05\omega$, $\gamma =0.01\omega$.

Figure 4

Color map for (a) quantum concurrence and (b) mutual information between the two qubits in the steady state at fixed $g=0.05\omega$ and qubit relaxation rate $\gamma =0.01\omega$ for different values of $\theta$ and cavity relaxation rate.

Figure 5

Color map for (a) the mean number of photons and (b) the population of the excited state of any of two qubits in the steady state at fixed $g=0.05\omega$ and qubit relaxation rate $\gamma =0.01\omega$ for different values of $\theta$ and cavity relaxation rate.

Figure 6

Color map for the time evolution of the conditional quantum concurrence $C_0$ for zero photon number and different values of parameter $\theta$ at $\kappa =0.001\omega$, $\gamma =0.01\omega$, and $g=0.05\omega$.