Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstraße 2, 30167, Hannover, Germany.
Laboratorium für Nano- und Quantenengineering, Leibniz Universität Hannover, Schneiderberg 39, 30167, Hannover, Germany.
Nano Lett. 2023 Jul 12;23(13):6109-6115. doi: 10.1021/acs.nanolett.3c01570. Epub 2023 Jun 28.
Large-scale quantum networks require the implementation of long-lived quantum memories as stationary nodes interacting with qubits of light. Epitaxially grown quantum dots hold great potential for the on-demand generation of single and entangled photons with high purity and indistinguishability. Coupling these emitters to memories with long coherence times enables the development of hybrid nanophotonic devices that incorporate the advantages of both systems. Here we report the first GaAs/AlGaAs quantum dots grown by the droplet etching and nanohole infilling method, emitting single photons with a narrow wavelength distribution (736.2 ± 1.7 nm) close to the zero-phonon line of silicon-vacancy centers. Polarization entangled photons are generated via the biexciton-exciton cascade with a fidelity of (0.73 ± 0.09). High single photon purity is maintained from 4 K (g(0) = 0.07 ± 0.02) up to 80 K (g(0) = 0.11 ± 0.01), therefore making this hybrid system technologically attractive for real-world quantum photonic applications.
大规模量子网络需要实现长寿命量子存储器作为与光量子相互作用的静止节点。外延生长的量子点具有很大的潜力，可以按需产生具有高纯度和不可分辨性的单光子和纠缠光子。将这些发射器与具有长相干时间的存储器耦合，可以开发出混合纳米光子器件，从而结合两个系统的优势。在这里，我们报告了首次通过液滴蚀刻和纳米孔填充方法生长的 GaAs/AlGaAs 量子点，其发射的单光子具有接近硅空位中心零声子线的窄波长分布（736.2 ± 1.7nm）。通过双激子-激子级联产生偏振纠缠光子，保真度为（0.73 ± 0.09）。从 4 K（g(0) = 0.07 ± 0.02）到 80 K（g(0) = 0.11 ± 0.01），单光子纯度保持不变，因此，这种混合系统在实际量子光子应用中具有技术吸引力。
