We report on the experimental observation of a hitherto ignored long-range electromagnetic coupling between self-assembled InAs/GaAs quantum dots (QDs). A 12 times enhancement of the QD exciton lifetime is observed by means of time-resolved differential reflection spectroscopy. The enhancement is due to local field effects within the QD ensemble. The electromagnetic coupling of the QDs results in a collective polarizability, and is observed as a suppression of the emission rate. Our results reveal that the mutual coupling strength can be optically tuned by varying the pump excitation density. This enables us to optically tune the exciton lifetime.
Bogaart, E. W., & Haverkort, J. E. M. (2010). Anomalous exciton lifetime by electromagnetic coupling of self-assembled InAs/GaAs quantum dots. Journal of Applied Physics, 107(6), 064313-1/5. . https://doi.org/10.1063/1.3354080