Suppressed antibunching via spectral filtering: An analytical study in the two-photon Mollow regime
Julian Schleibner, S. Bounouar, Max Strauß, Stephan Reitzenstein, Andreas Knorr, Alexander Carmele · Physical Review A · 2019
Mollow physics in the two-photon regime shows interesting features such as versatile generation of highly correlated photon pairs, timely ordered and energy tunable. Here, we calculate analytically the power spectral density $S(\ensuremath{\omega})$ and the two-photon correlations ${g}^{(2)}(\ensuremath{\tau})$, which are essential to discuss and study such phenomena in the resonant-driven dressed-state regime. It is shown that there exist upper and lower bounds of the ${g}^{(2)}(\ensuremath{\tau})$ function for certain spectrally selected photon pairs. Recently reported experiments agree with the presented theory and thereby it is shown that the resonant-driven four-level system is an interesting source for steerable quantum light in quantum cascade setups. We furthermore discuss the unlikeliness of observing antibunching for the delay time $\ensuremath{\tau}=0$ in the exciton-biexciton correlation functions in such experiments, since antibunching stems from a coherent and in-phase superposition of different photon-emission events. Due to the occurring laser photon scattering, this coherent superposition state is easily disturbed and leads to correlation functions of ${g}^{(2)}(0)=1$.