Semiconductor devices are strong competitors in the race for the development of quantum computational systems. In this work, we interface two semiconductor building blocks of different dimensionalities with complementary properties: (1) a quantum dot hosting a single exciton and acting as a nearly ideal single-photon emitter and (2) a quantum well in a 2D microcavity sustaining polaritons, which are known for their strong interactions and unique hydrodynamic properties, including ultrafast real-time monitoring of their propagation and phase mapping. In the present experiment, we can thus observe how the injected single particles propagate and evolve inside the microcavity, giving rise to hydrodynamic features typical of macroscopic systems despite their genuine intrinsic quantum nature. In the presence of a structural defect, we observe the celebrated quantum interference of a single particle that produces fringes reminiscent of wave propagation. While this behavior could be theoretically expected, our imaging of such an interference pattern, together with a measurement of antibunching, constitutes the first demonstration of spatial mapping of the self-interference of a single quantum particle impinging on an obstacle.

中文翻译：

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单个粒子的量子流体动力学。

在开发量子计算系统的竞赛中，半导体器件是强有力的竞争者。在这项工作中，我们将具有互补特性的两个不同维度的半导体构件连接在一起：（1）承载单个激子并充当几乎理想的单光子发射器的量子点；（2）维持极化子的2D微腔中的量子阱，以其强大的相互作用和独特的流体动力学特性而闻名，包括对其传播和相图的超快速实时监控。因此，在本实验中，我们可以观察到注入的单个粒子如何在微腔内传播和演化，尽管它们具有真正的内在量子性质，却产生了宏观系统中典型的流体动力学特征。在存在结构缺陷的情况下，我们观察到著名的单个粒子的量子干涉，该粒子产生的条纹让人联想到波的传播。尽管从理论上可以预期到这种行为，但是我们对这种干涉图样的成像以及对反聚束的测量，构成了对单个量子粒子撞击到障碍物上的自干涉的空间映射的首次展示。