Spin‐Orbit Coupled Trapped Exciton–Polariton Condensates in Perovskite Microcavity

Abstract Lead halide perovskites exhibit superior properties compared to classical III–V semiconductor quantum wells for room‐temperature polaritonic applications, particularly owing to the significant crystalline anisotropy. This anisotropy results in a sizeable split in condensate energy, which can profoundly influence polariton interactions and spin relaxation pathways. Besides, trapped exciton‐polariton (TEP) exhibits a quantized energy landscape, which is essential for modulating polaritonic logical circuits. Herein, spin‐orbit coupled TEP lasing is demonstrated in birefringent perovskite. Cascade condensate processes between orthogonally polarized polariton branches happen considering the dominance of reservoir exciton–polariton or polariton–polariton scattering within each stage. Such condensation adequately is verified via the input‐output “S” curve, the narrowed linewidth, the energy blueshift, and the real space spatial coherence of the orthogonally polarized modes. This trapped anisotropic condensate holds great promise for room‐temperature polaritonic and spintronics.