Observation of exciton polariton condensation in a perovskite lattice at room temperature

• Main Authors: Su, Rui, Ghosh, Sanjib, Wang, Jun, Liu, Sheng, Diederichs, Carole, Liew, Timothy Chi Hin, Xiong, Qihua
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2020
• Subjects: Science::Physics::Optics and light; Exciton Polariton; Perovskite
• Online Access: https://hdl.handle.net/10356/138202; https://doi.org/10.21979/N9/EZLMHJ
• Institution: Nanyang Technological University

Exciton polaritons, with extremely low effective mass1, are regarded as promising candidates to realize Bose–Einstein condensation in lattices for quantum simulations2 towards room-temperature operations3–8. Along with the condensation, an efficient exciton polariton quantum simulator9 would require a strong lattice with robust polariton trapping as well as strong intersite coupling to allow coherent quantum motion of polaritons within the lattice. A strong lattice can be characterized with a larger forbidden bandgap opening and a larger lattice bandwidth compared with the linewidth. However, exciton polaritons in such strong lattices have only been shown to condense at cryogenic temperatures3–8. Here, we report the observation of non-equilibrium exciton polariton condensation in a one-dimensional strong lead halide perovskite lattice at room temperature. Modulated by deep periodic potentials, the strong lead halide perovskite lattice exhibits a large forbidden bandgap opening up to 13.3 meV and a lattice band up to 8.5 meV wide, which are at least 10 times larger than previous systems. Above a critical density, we observe polariton condensation into py orbital states with long-range spatial coherence at room temperature. Our result opens the route to the implementation of polariton condensates in quantum simulators at room temperature.