SAXON Q, a Leipzig University spin-off, began taking orders on July 21, 2026, for two diamond quantum computers, the SXQ128 and the SXQ512. In its announcement, the company said the machines have 128 and 512 qubits, operate at room temperature, and fit in a standard server rack.
SAXON Q said the SXQ128 has eight “fully entangled” qubits per core and the SXQ512 has 16 per core, all of them physical qubits.
SAXON Q counted 128 qubits by adding up cores of eight physical qubits each, and it cited no paper, benchmark, or independent test of the new machines’ performance.
What SAXON Q counts as a qubit
SAXON Q builds its processors from nitrogen-vacancy (NV) centers, defects in diamond in which a nitrogen atom takes the place of a carbon atom next to an empty site in the crystal. In a whitepaper on its earlier QC2026 Dual Core system, the company described each quantum node as one NV center and three to nine nuclear spins, for four to 10 qubits per node. Nuclear spin is a magnetic property of atomic nuclei.
The whitepaper’s specification table lists two cores of four or five qubits each for the Dual Core. SAXON Q wrote that the cores can work separately on different jobs or as one parallel system, with problems divided by circuit cutting. In that technique, pieces of a circuit run on separate cores and a classical computer recombines the results.
Circuit cutting “introduces significant classical computation overhead and does not scale well for highly entangled problems,” SAXON Q wrote. “A key open issue remains the quantum mechanical connection of these cores,” the company added.
Performance figures
SAXON Q said that qubits made with its fabrication process “achieve up to 99.92% fidelity.” The company did not name the operation, say how many qubits it had measured, or describe its method. Fidelity is a measure of how closely a quantum state or operation matches its intended result.
In the whitepaper, SAXON Q listed single-qubit gate fidelities of “up to 0.9992” and a two-qubit gate fidelity of 0.97 for its third-generation system, next to higher simulated values. A figure in the whitepaper attributes the one-qubit fidelities of that system’s nuclear-spin qubits to randomized benchmarking, a method that measures the average error over long random sequences of gates. The company did not say how it obtained the 0.97 figure. A two-qubit gate is an operation on two qubits, the kind used to entangle them.
SAXON Q also said the systems are 6 to 10 times more energy-efficient than GPU-based approaches. It did not name the workloads or say how it made the comparison.
Diamond fabrication
SAXON Q said its sulfur co-implantation process, which adds sulfur atoms to the diamond along with the nitrogen, converts more than 85% of implanted nitrogen into NV centers, against 1% to 10% for traditional methods. It cited no paper for the figure.
In a 2019 paper in Nature Communications, Leipzig University physicists including Jan Meijer, a SAXON Q co-founder, reported an NV creation yield of 75% in sulfur-doped diamond, against about 6% to 8% in undoped diamond. The authors calculated the yield as the number of NV centers formed per implanted nitrogen atom.
Earlier systems
In July 2024, the German Aerospace Center (DLR) accepted a four-qubit SAXON Q system after verifying SAXON Q’s measurements with its own tests. SAXON Q had to show gate quality above 95% for one-qubit gates and above 90% for two-qubit gates on all four qubits. DLR said it set a single lower fidelity limit for the whole register instead of picking the best individual results.
DLR has offered the system to partners through its QCI Connect platform since August 2025. Fraunhofer IWU in Dresden has operated a second four-qubit SAXON Q system since June 2025.
SAXON Q said it would deliver the SXQ128 within three months of an order and begin SXQ512 deliveries in the second quarter of 2027. In a roadmap table in the whitepaper, the company projected 128 cores and more than 10,000 qubits by 2030.
Update, November 12, 2026: In September, researchers including Meijer and Albrecht Hänel of Fraunhofer IWU reported a Grover search on three nuclear-spin qubits with a single-target success rate of 77.3%. The Quantum Insider reported that the experiment ran on the system installed at Fraunhofer IWU in 2025. No public report of an SXQ128 delivery or an independent test had appeared as of November 12.
