Discrete frequency-bin entanglement generation via cascaded second-order nonlinear processes in Sagnac interferometer
| Autor: | Jiarui Li, Chenzhi Yuan, Si Shen, Zichang Zhang, Ruiming Zhang, Hao Li, You Wang, Guangwei Deng, Lixing You, Zhen Wang, Haizhi Song, Yunru Fan, Guangcan Guo, Qiang Zhou |
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| Rok vydání: | 2023 |
| Předmět: | |
| DOI: | 10.48550/arxiv.2304.14245 |
| Popis: | Discrete frequency-bin entanglement is an essential resource for applications in quantum information processing. In this Letter, we propose and demonstrate a scheme to generate discrete frequency-bin entanglement with a single piece of periodically poled lithium niobate waveguide in a modified Sagnac interferometer. Correlated two-photon states in both directions of the Sagnac interferometer are generated through cascaded second-order optical nonlinear processes. A relative phase difference between the two states is introduced by changing the polarization state of pump light, thus manipulating the two-photon state at the output of the Sagnac interferometer. The generated two-photon state is sent into a fiber polarization splitter, then a pure discrete frequency-bin entangled two-photon state is obtained by setting the pump light. The frequency entanglement property is measured by a spatial quantum beating with a visibility of $96.0 \pm 6.1\%$. The density matrix is further obtained with a fidelity of $98.0 \pm 3.0\%$ to the ideal state. Our demonstration provides a promising method for the generation of pure discrete frequency-bin entanglement at telecom band, which is desired in quantum photonics. Comment: 4 pages. 3 figures |
| Databáze: | OpenAIRE |
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