Chen Chen, Yan Jun-Yong, Babin Hans-Georg, Wang Jiefei, Xu Xingqi, Lin Xing, Yu Qianqian, Fang Wei, Liu Run-Ze, Huo Yong-Heng, Cai Han, Sha Wei E I, Zhang Jiaxiang, Heyn Christian, Wieck Andreas D, Ludwig Arne, Wang Da-Wei, Jin Chao-Yuan, Liu Feng
State Key Laboratory of Extreme Photonics and Instrumentation, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310027, China.
Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, 44801, Bochum, Germany.
Nat Commun. 2024 Jul 10;15(1):5792. doi: 10.1038/s41467-024-50062-0.
The construction of a large-scale quantum internet requires quantum repeaters containing multiple entangled photon sources with identical wavelengths. Semiconductor quantum dots can generate entangled photon pairs deterministically with high fidelity. However, realizing wavelength-matched quantum-dot entangled photon sources faces two difficulties: the non-uniformity of emission wavelength and exciton fine-structure splitting induced fidelity reduction. Typically, these two factors are not independently tunable, making it challenging to achieve simultaneous improvement. In this work, we demonstrate wavelength-tunable entangled photon sources based on droplet-etched GaAs quantum dots through the combined use of AC and quantum-confined Stark effects. The emission wavelength can be tuned by ~1 meV while preserving an entanglement fidelity f exceeding 0.955(1) in the entire tuning range. Based on this hybrid tuning scheme, we finally demonstrate multiple wavelength-matched entangled photon sources with f > 0.919(3), paving the way towards robust and scalable on-demand entangled photon sources for quantum internet and integrated quantum optical circuits.
构建大规模量子互联网需要包含多个具有相同波长的纠缠光子源的量子中继器。半导体量子点可以高保真地确定性地产生纠缠光子对。然而，实现波长匹配的量子点纠缠光子源面临两个困难：发射波长的不均匀性和激子精细结构分裂导致的保真度降低。通常，这两个因素不能独立调节，因此难以同时实现改进。在这项工作中，我们通过结合使用交流和量子限制斯塔克效应，展示了基于液滴蚀刻砷化镓量子点的波长可调纠缠光子源。发射波长可以在整个调谐范围内调谐约1毫电子伏特，同时保持纠缠保真度f超过0.955(1)。基于这种混合调谐方案，我们最终展示了多个保真度f > 0.919(3)的波长匹配纠缠光子源，为量子互联网和集成量子光学电路的强大且可扩展的按需纠缠光子源铺平了道路。
