Hefei Startup and USTC Demonstrate 16-Qubit On-Chip Photonic MBQC Architecture

Chinese startup Hefei Guizhen Chip Technology Co., Ltd. (硅臻芯片), in collaboration with Professor Ren Xifeng‘s team at the Chinese Academy of Sciences (CAS) Key Laboratory of Quantum Information at the University of Science and Technology of China (USTC), has published research demonstrating a 16-qubit measurement-based quantum computing (MBQC) system on a single silicon photonic chip. Detailed in an August 2026 pre-print (“On-chip generation of multi-qubit graph states with high-dimensional encoded single photons“), the experiment achieved a 98.7% average identification probability executing Grover’s search algorithm across four search targets—outperforming the prior 4-qubit on-chip photonic MBQC benchmark of 80.8% set by the University of Stuttgart (“Measurement-Based Quantum Computing on a Photonic Chip“).

To overcome the exponential coincidence-rate loss that occurs when attempting to entangle multiple distinct single-photon sources, the Guizhen Chip and USTC team utilized high-dimensional path encoding. By routing each photon across 16 distinct waveguide paths on a standard silicon-on-insulator (SOI) platform, the chip encodes a 4-level qudit (carrying 4 qubits of quantum information) per photon. This 4-photon, 16-qubit architecture avoids probabilistic multi-photon interactions during execution:

• High-Dimensional Compression: 4 photons carry a 16-qubit Greenberger-Horne-Zeilinger (GHZ) and cluster graph state, reducing multi-photon coincidence demands from O(2¹⁶) to O(2⁴).
• Genuine Multipartite Entanglement: Entanglement witnessing certified genuine multipartite entanglement across 10 of the 16 path-encoded qubits.
• Programmable MBQC Layers: Four layers of Mach-Zehnder interferometers and thermo-optic phase shifters execute adaptive single-qubit measurements driven by real-time classical feedback loops.

                    [ High-Dimensional Path-Encoded Photonic MBQC ]
                                           │
     ┌─────────────────────────────────────┴─────────────────────────────────────┐
     ▼                                                                           ▼
  Silicon Waveguide Path Encoding (4 Qubits/Photon)             Adaptive Measurement Layers (MBQC Model)
  • 4 Photons routed through 16 Waveguide Modes.                • Mach-Zehnder Interferometer Arrays.
  • Generates 16-Qubit GHZ & Cluster Resource States.           • Real-time Adaptive Thermo-Optic Phase Shifting.
  • Certified 10-Qubit Genuine Multipartite Entanglement.       • 98.7% Grover Search Algorithm Accuracy.

While high-dimensional path encoding bypasses multi-photon coincidence bottlenecks, it amplifies photon-loss penalties: losing a single photon dissipates 4 qubits of state information simultaneously. The pre-print remains subject to formal peer review to verify experimental transmission loss profiles and entanglement witnessing metrics. If validated, high-fidelity 16-qubit on-chip resource-state generation provides a critical component-level demonstration for fusion-based quantum computing (FBQC) architectures pursued by global photonic hardware developers.

Review the report on Tech Times here, examine the USTC high-dimensional encoding paper on arXiv here, and inspect the University of Stuttgart MBQC research on arXiv here.

August 11, 2026