Wavelength-tunable high-fidelity entangled photon sources enabled by dual Stark effects

• Published in: arXiv.org
• Main Authors: Chen, Chen, Jun-Yong, Yan, Babin, Hans-Georg, Wang, Jiefei, Xu, Xingqi, Lin, Xing, Yu, Qianqian, Fang, Wei, Liu, Run-Ze, Yong-Heng Huo, Cai, Han, Sha, Wei E I, Zhang, Jiaxiang, Heyn, Christian, Wieck, Andreas D, Ludwig, Arne, Da-Wei, Wang, Chao-Yuan, Jin, Liu, Feng
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 22.04.2024
• Subjects: Accuracy; Excitons; Fine structure; Internet; Nonuniformity; Photons; Physics - Quantum Physics; Quantum dots; Repeaters
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2308.04744

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 a way towards robust and scalable on-demand entangled photon sources for quantum internet and integrated quantum optical circuits.