Controlling spontaneous emission via electronic correlations and temperature in transparent oxides

We study spontaneous emission of two-level quantum emitter agglomerates embedded in transparent oxides. The two levels correspond to the splitting between vacancy impurity states F,F+, and V− color centers, whereas correlations are due to narrow bands in transition-metal oxides with ABO3 perovskite structures. For these systems, we put forward a mechanism to control light emission in which micrometer-size vacancy-rich regions play the role of cavity resonators for the emitted radiation with normal frequencies mode volumes, and emission linewidths determined by their size and material properties. We argue that a physical scenario in which the emitter's natural frequency and linewidth can be fine-tuned via electronic correlations or temperature explains unusual features in the experimental photoluminescence spectra of Ar-irradiated SrTiO3. By unveiling the role of electronic correlations on spontaneous emission in transparent oxides, we hope our findings help set the basis for the design of controllable engineered solid-state single-photon sources.