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DOE OSTI · 2429777

Building a controlled-NOT gate between polarization and frequency

Lu, Hsuan-Hao (ORCID:0000000340090787)·Lukens, Joseph M. (ORCID:0000000196504462)·Alshowkan, Muneer (ORCID:0000000264293450)·Kirby, Brian T. (ORCID:0000000226989887)·Peters, Nicholas A. (ORCID:0000000272159630)
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Abstract

By harnessing multiple degrees of freedom (DoFs) within a single photon, controlled quantum unitaries, such as the two-qubit controlled-NOT ( cnot ) gate, play a pivotal role in advancing quantum communication protocols such as dense coding and entanglement distillation. In this work, we devise and realize a cnot operation between polarization and frequency DoFs by exploiting directionally dependent electro-optic phase modulation within a fiber Sagnac loop. Alongside computational basis measurements, we validate the effectiveness of this operation through the synthesis of all four Bell states in a single photon, all with fidelities greater than 98%. This demonstration opens new avenues for manipulating hyperentanglement across these two crucial DoFs, marking a foundational step toward leveraging polarization-frequency resources in fiber networks for future quantum applications.

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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS

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Lu, Hsuan-Hao (ORCID:0000000340090787), Lukens, Joseph M. (ORCID:0000000196504462), Alshowkan, Muneer (ORCID:0000000264293450), Kirby, Brian T. (ORCID:0000000226989887), Peters, Nicholas A. (ORCID:0000000272159630). 2024-08-16. Building a controlled-NOT gate between polarization and frequency. https://doi.org/10.1364/opticaq.525837

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