Xanadu has reported the generation of a Gottesman–Kitaev–Preskill (GKP) qubit using a fully integrated photonic chip fabricated on a silicon nitride platform. The result, published in Nature, demonstrates that GKP states—long considered a critical ingredient for error-corrected bosonic quantum architectures—can be created using silicon nitride photonic circuits fabricated on 300 mm wafers. The chip integrates squeezed-state generation, linear optics, and high-efficiency photon-number-resolving detectors, enabling direct synthesis of GKP states with clear nonclassical structure.
The experimental platform routes laser pulses through integrated optical waveguides, where they undergo squeezing and programmable unitary transformations. Heralding via Gaussian boson sampling identifies valid multiphoton events that encode GKP states. The generated states show four resolvable peaks in each quadrature and a 3×3 grid of negative Wigner function regions—hallmarks of high-fidelity GKP encoding. All components are implemented on-chip, and the system operates at room temperature without cryogenic infrastructure, supporting the long-term vision of photonic quantum data centers.
GKP qubits offer a significant advantage over traditional photonic encodings by enabling deterministic logic gates and natural error correction using bosonic modes. Xanadu’s result confirms that the integration challenges of squeezing, loss suppression, and detection can be overcome in a single device. Although the current implementation is probabilistic, multiplexing strategies and additional loss reduction are planned to increase the yield of high-quality states suitable for large-scale computation.
This demonstration validates a key element in Xanadu’s roadmap toward modular, networked photonic quantum processors. With previous milestones including its Aurora system and progress on linear optical components, the company now has all major subsystems required for scalable photonic fault tolerance. Further improvements will target qubit quality, on-demand generation, and hardware integration to support quantum architectures at data center scale.
Read the official announcement here, the official Xanadu blog post here, the Nature research briefing here, and the full research article here.
June 5, 2025
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