Tunable exciton–polariton condensation in a two-dimensional Lieb lattice at room temperature

Abstract

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.

Artificial periodic lattices of microcavities filled with optically active materials can serve as a platform to explore a range of physical phenomena. Here, the authors prepare and analyse 2D Lieb lattices made from a tunable cavity array with an organic polymer which operates in the strong exciton–photon coupling regime and exhibits polariton condensation at room temperature.