Microcavities with embedded optically active materials allow to create exciton–polariton condensates in the strong light–matter interaction regime. These condensates exhibit quantum fluid properties up to room temperature, and, when crystal-like lattices are imprinted in the cavity, they can be used to emulate and study solid-state physics toy models. Here, we demonstrate room temperature polariton condensation in a nano-fabricated two-dimensional Lieb lattice with an organic polymer. We exploit the tunability of our open cavity to selectively condense into the s-, p- and d-lattice band manifolds. Furthermore, we interferometrically measure long-range first-order coherence across the lattice and assess the influence of the disorder in the system. These are key first steps to investigate extended topological polariton systems at ambient conditions.

嵌入了光学活性材料的微腔可以在强光-物质相互作用的情况下产生激子-极化子冷凝物。这些冷凝物在室温下仍表现出量子流体性质，并且当在腔体中印上类似晶体的晶格时，它们可用于模拟和研究固态物理玩具模型。在这里，我们展示了有机聚合物在纳米二维二维李布晶格中的室温极化子凝聚。我们利用开放腔的可调谐性选择性地凝结为s-，p-和d-晶格带流形。此外，我们采用干涉法测量了整个晶格的远程一阶相干性，并评估了系统中无序的影响。这些是研究环境条件下扩展的拓扑极化子系统的关键的第一步。