Generating entanglement between quantum dots with different resonant frequencies based on dipole-induced transparency

We describe a method for generating entanglement between two spatially separated dipoles coupled to optical microcavities. The protocol works even when the dipoles have different resonant frequencies and radiative lifetimes. This method is particularly important for solid-state emitters, such as quantum dots, which suffer from large inhomogeneous broadening. We show that high fidelities can be obtained over a large dipole detuning range without significant loss of efficiency. We analyze the impact of higher-order photon number states and cavity resonance mismatch on the performance of the protocol.

Figure 1

(Color online) Schematic of cavity waveguide system for generating entanglement between two spatially separated dipoles using DIT.

Figure 2

(Color online) Variation of fidelity and efficiency with ${\mid \alpha r_1^g\mid }^2$ for different values of ${\delta }_1$.

Figure 3

(Color online) Efficiency as a function of ${\delta }_1∕\kappa$ for different ${\delta }_2$. Fidelity is fixed at 0.85.

Figure 4

(Color online) Fidelity as a function of laser frequency for different values of ${\Delta }_1$. Optimization is performed over the real and imaginary parts of $\alpha ∕\beta$. Cavity separation $\Delta {\omega }_s$ is set to $50\mathrm{GHz}$ and ${\Delta }_2=0.25\kappa \mathrm{GHz}$.

Figure 5

(Color online) Optimized fidelity as a function of $\Delta {\omega }_s$ for different values of ${\Delta }_1$. ${\Delta }_2=0$.

Figure 6

(Color online) Fidelity as a function of cavity separations $\Delta {\omega }_s$ and dipole detuning ${\Delta }_1$.

Figure 7

(Color online) QD as a three-level system.

Figure 8

(Color online) Fidelity as a function of dipole detunings ${\delta }_1$ and ${\delta }_2$ for the exciton-biexciton model of a QD.