Figure 3

(a) A singly charged QD inside a double-sided cavity interacting with a photon where the decay rate (γ) of X− and the side leakage rate (κ s ). (b) The spin selection rule for optical transitions of X− in the QD \(|\,\uparrow \rangle \to |\uparrow \downarrow \Uparrow \rangle \) (\(|\,\downarrow \rangle \to |\downarrow \uparrow \Downarrow \rangle \)) is driven by the photon \(|{L}^{\downarrow }\rangle ,|{R}^{\uparrow }\rangle \) (\(|{R}^{\downarrow }\rangle ,|{L}^{\uparrow }\rangle \)). The symbol \(\uparrow \) (\(\downarrow \)) of photon represents the spin projection along (against) the quantization axis (z direction).