Strongly coupled semiconductor microcavities: A route to couple artificial atoms over micrometric distances

We fabricate closely spaced microdisk resonators with embedded quantum dots (QDs) as emitters. By continuously tuning the refractive index of one of the microcavities, we observe clear molecularlike modes with ``bonding'' and ``antibonding'' characters, as confirmed by detailed finite-difference time-domain simulations. Based on recent reports on strong coupling between a single QD and a cavity mode, we propose to use modes in ``photonic molecules'' as a means to coherently transfer excitation between resonant QDs placed in different cavities.