Two-photon pumped exciton-polariton condensation

Two-photon absorption (TPA) allows accessing “dark” states of matter that are otherwise inaccessible to light, which serve as important building blocks for quantum information processing. In a semiconductor microcavity, TPA-driven condensation strongly coupled light-matter exciton–polaritons can enable new solid-state simulations state-condensate interactions and was predicted stimulate THz emission. Here, we report the first observation two-photon-pumped polariton condensation, demonstrated by angle-resolved photoluminescence in GaAs-based microcavity. TPA is evidenced quadratic emission dependence on pump power below above threshold, second-harmonic generation ruled out both this threshold behavior peak energy showing no photon energy. Our results pave way toward novel polariton-based sources coherent control collective with individual two-level systems.