First on-chip photonic qubit enables GKP states for error correction at room temperature

Sadie Harley
scientific editor

Robert Egan
associate editor

Xanadu has achieved a significant milestone in the development of scalable quantum hardware by generating error-resistant photonic qubits on an integrated chip platform. A foundational result in Xanadu's roadmap, this first-ever demonstration of such qubits on a chip is published in .
This advance builds on Xanadu's recent announcement of the Aurora system, which demonstrated—for the first time—all key components required to build a modular, networked, and scalable photonic quantum computer. With this latest demonstration of robust qubit generation using silicon-based photonic chips, Xanadu further strengthens the scalability pillar of its architecture.
The quantum states produced in this experiment, known as Gottesman–Kitaev–Preskill (GKP) states, consist of superpositions of many photons to encode information in an error-resistant manner—an essential requirement for future fault-tolerant quantum computers. These states allow logic operations to be performed using deterministic, room-temperature-compatible techniques, and they are uniquely well-suited for networking across chips using standard fiber connections.
This demonstration of generating photonic qubits was enabled by a number of key technological achievements from Xanadu's hardware team. These include the development of photon-number-resolving detectors with detection efficiencies above 99%, the fabrication of customized ultra-low-loss silicon nitride waveguides on 300 mm wafer platforms, and the implementation of in-house state-of-the-art optical packaging.

"GKP states are, in a sense, the optimal photonic qubit, since they enable logic gates and error correction at room temperature and using relatively straightforward, deterministic operations," says Zachary Vernon, CTO of Hardware at Xanadu.
"This demonstration is an important empirical milestone showing our recent successes in loss reduction and performance improvement across chip fabrication, component design, and detector efficiency."
The next hurdle towards a utility-scale photonic quantum computer remains clear: further reduction of optical loss will allow for higher quality GKP states suitable for fault-tolerance.
With another significant milestone in its hardware roadmap complete, Xanadu remains focused on further optimizing fabrication and photonics packaging processes to alleviate optical loss across its platform.
More information: M. V. Larsen et al, Integrated photonic source of Gottesman–Kitaev–Preskill qubits, Nature (2025).
Journal information: Nature
Provided by Xanadu Quantum Technologies Inc.