In the last decade, a new field of “polaritonics” is emerging as a highly promising alternative to purely photonic and electronic systems. Specifically, in semiconductor microcavities, huge nonlinearities can be obtained, when excitons are strongly coupled to cavity photons producing new exciton-photon states called polaritons. Polaritons, which are hybrid states of light and electronic excitations, offer an attractive solution as they are a natural bridge between these two systems. Their excitonic component allows them to interact strongly, giving rise to the nonlinear functionality enjoyed by electrons. On the other hand, their photonic component restricts their dephasing, allowing them to carry information with minimal data loss.
Recent work on microcavities has shed light on the bosonic properties of polaritons in the strong coupling regime, with spectacular demonstrations of bosonic stimulated scattering of polaritons , polariton amplification and condensation at relatively high temperatures inspiring a remarkable amount of new work on the polariton lasing and superfluidity within the condensed state . These recent discoveries open a breathtaking perspective of the practical use of these coherent quantum effects in a new generation of opto- and micro-electronic devices. Furthermore, the macroscopic quantum properties of polariton condensates, combined with their photonic nature, make them ideal candidates for their use in quantum information devices and all optical circuits.