Fujitsu Fabricates Diamond-Spin QPU Prototype Integrating Tin-Vacancy Centers and Photonic ICs

Fujitsu Fabricates Diamond-Spin QPU Prototype Integrating Tin-Vacancy Centers and Photonic ICs Japanese IT group Fujitsu Limited has announced a physical hardware milestone in solid-state quantum architectures, fabricating a working prototype diamond-spin quantum processing unit (QPU) that integrates tin-vacancy (SnV) color centers directly into photonic integrated circuits (PICs). Developed in collaboration with QuTech (TU Delft) and the University of Tokyo, the platform operates at a cryogenic temperature of -271.6°C (1.55 Kelvin)—substantially warmer than the ~15 millikelvin regime required by superconducting processors—and has been deployed for remote cloud access through the Fujitsu Hybrid Quantum Computing Platform. The chip fabrication process addresses structural scaling challenges inherent to color-center quantum hardware through heterogeneous material bonding and nanometer-scale diamond thinning. High-quality diamond substrates ion-implanted with tin atoms are surface-activated and bonded to alumina/silicon dioxide (Al2O3/SiO2) carrier substrates, then thinned down from hundreds of micrometers to sub-micron layers. Nanometer-sized diamond crystals hosting SnV centers are coupled to alumina (Al2O3) optical waveguides—selected for low optical loss across visible wavelengths—allowing single photons emitted during qubit readout and entanglement generation to be extracted directly on-chip. In contrast to traditional nitrogen-vacancy (NV) centers, SnV color centers feature structural inversion symmetry within the diamond lattice, making electronic spin states significantly less sensitive to local electric field noise. Furthermore, SnV centers exhibit 10× higher photon emission brightness than NV centers, providing the optical photon flux required for high-efficiency inter-module optical interconnects. Coupled with carbon-13 (13C) nuclear spins functioning as local quantum memory (coherence times T2 > 1 minute for nuclear spins and > 1 second for electron spins), the architecture establishes a modular pathway to inter-chip quantum state transfer using 50:50 beam splitters and single-photon detectors without requiring microwave-to-optical transducers. To control multi-module operations, Fujitsu implemented a software-defined, real-time control system managed via field-programmable gate arrays (FPGAs). The control stack decouples operations into a global controller processor—which orchestrates multi-module instruction sequences—and local processors that generate RF, microwave, and laser control pulses for individual diamond modules. This asynchronous control model handles variable execution times across distributed modules, mitigating latency bottlenecks as the physical quantum footprint expands. Fujitsu plans to deploy a multi-module diamond-spin prototype by 2027 to advance its roadmap toward a 250 logical qubit system by FY2030 and a 1,000 logical qubit system by FY2035. Additionally, Fujitsu is developing physical interface technologies to optically link its diamond-spin modules with its parallel 10,000+ physical qubit superconducting hardware roadmap, creating a heterogeneous quantum computing architecture. Review the official press release on Fujitsu Limited here, inspect the technical presentation via Fujitsu Research PDF here, and access platform specs on the Fujitsu Diamond-Spin Portal here. September 8, 2026 Mohamed Abdel-Kareem2026-09-08T09:26:49-07:00 Leave A Comment Cancel replyComment Type in the text displayed above Δ This site uses Akismet to reduce spam. Learn how your comment data is processed.