2025-02-04 オークリッジ国立研究所(ORNL)
＜関連情報＞
- https://www.ornl.gov/news/quantum-researchers-develop-first-its-kind-quantum-gate
- https://opg.optica.org/opticaq/fulltext.cfm?uri=opticaq-2-4-282&id=554693&utm
- https://opg.optica.org/opticaq/fulltext.cfm?uri=opticaq-2-4-254&id=554524&utm
偏波と周波数間の制御されたNOTゲートの構築 Building a controlled-NOT gate between polarization and frequency
Hsuan-Hao Lu, Joseph M. Lukens, Muneer Alshowkan, Brian T. Kirby, and Nicholas A. Peters
Optica Quantum Published: August 16, 2024
DOI:https://doi.org/10.1364/OPTICAQ.525837
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.
広帯域偏光もつれ光子のCMOSフォトニック集積光源 CMOS photonic integrated source of broadband polarization-entangled photons
Alexander Miloshevsky, Lucas M. Cohen, Karthik V. Myilswamy, Muneer Alshowkan, Saleha Fatema, Hsuan-Hao Lu, Andrew M. Weiner, and Joseph M. Lukens
Optica Quantum Published: August 12, 2024
DOI:https://doi.org/10.1364/OPTICAQ.521418
Abstract
We showcase a fully on-chip CMOS-fabricated silicon photonic integrated circuit employing a bidirectionally pumped microring and polarization splitter-rotators tailored for the generation of broadband (>9 THz), high-fidelity (90–98%) polarization-entangled photons. Spanning the optical C+L-band and producing over 116 frequency-bin pairs on a 38.4-GHz-spaced grid, this source is ideal for flex-grid wavelength-multiplexed entanglement distribution in multiuser networks.
