Lead halide perovskites exhibit good performance in room-temperature exciton–polariton lasers and efficient flow of polariton condensates. Shaping and directing polariton condensates by confining the potential is essential for polariton-based optoelectronic devices, which have seldom been explored based on perovskite materials. Here, we investigate the trapping of polaritons in micron-sized CsPbBr₃ flakes embedded in a microcavity by varying the negative detuning energy (from −36 to −172 meV) at room temperature. The confinement by the crystal edge results in quantized polariton states both below and above the condensed threshold. As the cavity is more negatively detuned (Δ ≤ −118 meV), the condensed polaritons undergo a transition from the ground state to metastable states with a finite group velocity (∼50 μm/ps at Δ = −118 meV). The metastable polariton condensates can be optically and stably driven between different polariton states by simply changing the pump fluence. The manipulations of the polariton states reveal the effective control of polariton relaxation in quantized polariton states by the underlying exciton–polariton and polariton–polariton scattering. Our findings pave the way for novel polaritonic light sources and integrated polariton devices through the trap engineering of perovskite microcavities.

中文翻译：

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在钙钛矿型微腔中通过空间限制来捕获激子-极化子冷凝物

卤化钙钛矿在室温激子-极化子激光器中表现出良好的性能，并且极化子冷凝物有效流动。通过限制电势来塑造和引导极化子冷凝物对于基于极化子的光电器件至关重要，而基于极化钙钛矿的材料很少被探索。在这里，我们研究微米级CsPbBr ₃中极化子的捕获通过在室温下改变负失谐能量（从-36到-172 meV）将微片嵌入微腔。晶体边缘的限制导致在凝聚阈值之下和之上的量化极化子态。随着腔的负失调程度更大（Δ≤-118 meV），凝聚的极化子以有限的群速度（在Δ= -118 meV时约为50μm/ ps）经历从基态到亚稳态的跃迁。通过简单地改变泵浦注量，可以在不同的极化子状态之间光学稳定地驱动亚稳态极化子冷凝物。极化子态的操纵揭示了潜在的激子-极化子和极化子-极化子散射可以有效控制量化极化子态中极化子的弛豫。