加拿大Xanadu量子技术公司D. H. Mahler团队研究了Gottesman-Kitaev-Preskill量子比特的集成光子源。相关论文于2025年6月4日发表在《自然》杂志上。

构建一个有用的光子量子计算机需要稳健的技术来合成可以编码量子比特的光学态。Gottesman–Kitaev–Preskill（GKP）态提供了此类量子比特编码中最具吸引力的类别之一，因为它们能够实现具有简单、确定性和室温兼容高斯运算的通用门集。现有的产生光学GKP态和其他复杂非高斯态的开创性演示依赖于自由空间光学元件，阻碍了公用事业规模系统最终所需的缩放。 

研究组使用在定制的多层氮化硅300毫米晶片平台上制造的超低损耗集成光子芯片，通过光纤与高效光子数分辨探测器耦合，以产生GKP量子比特态。这些状态显示了容错所需的临界模式级特征，包括p和q象限中至少有四个可分辨的峰值，以及负维格纳函数区的清晰晶格结构，在这种情况下为3 × 3 grid。

研究组还表明，该GKP状态显示出足够的结构，表明用于制造它们的器件在进一步减少光损耗后，可以产生容错状态。该实验验证了光子量子计算的玻色子架构的一个关键支柱，为未来提供容错机器的GKP源阵列铺平了道路。

附：英文原文

Title: Integrated photonic source of Gottesman–Kitaev–Preskill qubits

Author: Larsen, M. V., Bourassa, J. E., Kocsis, S., Tasker, J. F., Chadwick, R. S., Gonzlez-Arciniegas, C., Hastrup, J., Lopetegui-Gonzlez, C. E., Miatto, F. M., Motamedi, A., Noro, R., Roeland, G., Baby, R., Chen, H., Contu, P., Di Luch, I., Drago, C., Giesbrecht, M., Grainge, T., Krasnokutska, I., Menotti, M., Morrison, B., Puviraj, C., Rezaei Shad, K., Hussain, B., McMahon, J., Ortmann, J. E., Collins, M. J., Ma, C., Phillips, D. S., Seymour, M., Tang, Q. Y., Yang, B., Vernon, Z., Alexander, R. N., Mahler, D. H.

Issue&Volume: 2025-06-04

Abstract: Building a useful photonic quantum computer requires robust techniques to synthesize optical states that can encode qubits. Gottesman–Kitaev–Preskill (GKP) states1 offer one of the most attractive classes of such qubit encodings, as they enable the implementation of universal gate sets with straightforward, deterministic and room temperature-compatible Gaussian operations2. Existing pioneering demonstrations generating optical GKP states3 and other complex non-Gaussian states4,5,6,7,8,9,10,11 have relied on free-space optical components, hindering the scaling eventually required for a utility-scale system. Here we use an ultra-low-loss integrated photonic chip fabricated on a customized multilayer silicon nitride 300-mm wafer platform, coupled over fibre with high-efficiency photon number resolving detectors, to generate GKP qubit states. These states show critical mode-level features necessary for fault tolerance, including at least four resolvable peaks in both p and q quadratures, and a clear lattice structure of negative Wigner function regions, in this case a 3×3 grid. We also show that our GKP states show sufficient structure to indicate that the devices used to make them could, after further reduction in optical losses, yield states for the fault-tolerant regime. This experiment validates a key pillar of bosonic architectures for photonic quantum computing2,12, paving the way for arrays of GKP sources that will supply future fault-tolerant machines.

DOI: 10.1038/s41586-025-09044-5

Source: https://www.nature.com/articles/s41586-025-09044-5