GaAs quantum dots in nanowires are one of the most promising candidates for scalable quantum photonics. They have excellent optical properties, can be frequency-tuned to atomic transitions, and offer a robust platform for fabrication of multi-qubit devices that promise to unlock the full technological potential of quantum dots. Coherent resonant excitation is necessary for virtually any practical application because it allows, for instance, for on-demand generation of single and entangled photons, photonic clusters states, and electron spin manipulation. However, emission from nanowire structures under this excitation scheme has never been demonstrated. Here we show, for the first time, biexciton–exciton cascaded emission via resonant two-photon excitation and resonance fluorescence from an epitaxially grown GaAs quantum dot in an AlGaAs nanowire. We also report that resonant excitation schemes, combined with above-bandgap excitation, can be used to clean and enhance the emission of nanowire quantum dots.

纳米线中的GaAs量子点是可扩展量子光子学最有希望的候选者之一。它们具有出色的光学性能，可以进行频率调谐至原子跃迁，并为制造多量子位器件提供了一个强大的平台，有望释放量子点的全部技术潜力。相干谐振激发实际上对于任何实际应用都是必需的，因为它允许例如按需生成单个和纠缠的光子，光子簇状态和电子自旋操纵。然而，从未证明在这种激发方案下来自纳米线结构的发射。在这里，我们首次展示了通过共振双光子激发和来自AlGaAs纳米线中外延生长的GaAs量子点的共振荧光产生的双激子-激子级联发射。