Rigetti Releases 108-Qubit Cepheus-1-108Q System via Cloud Platforms
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Rigetti Releases 108-Qubit Cepheus-1-108Q System via Cloud Platforms Rigetti Computing has announced the general availability of its Cepheus-1-108Q quantum computing system. The 108-qubit processor is accessible via the Rigetti Quantum Cloud Services (QCS) platform and Amazon Braket. This system represents a scaling of the company’s modular architecture, increasing the qubit count from its previous 36-qubit iteration. The deployment on Amazon Braket marks the first gate-based quantum device with over 100 qubits to be hosted on the AWS service. The architecture of the Cepheus-1-108Q consists of twelve interconnected 9-qubit chiplets. This modular approach allows for the tiling of multiple small-scale chips to form a larger processor, a method Rigetti uses to manage yield and complexity during fabrication. At launch, the system is reporting a 99.1% median two-qubit gate fidelity and a 99.9% median single-qubit fidelity. The system maintains gate speeds of approximately 60 nanoseconds, consistent with the characteristics of superconducting transmon qubits. Technical improvements in this generation include the use of Alternating-Bias Assisted Annealing, a fabrication technique designed to improve qubit frequency targeting and reduce defects on the chip. Rigetti also implemented upgraded control electronics intended to provide a higher signal-to-noise ratio for qubit readout. To mitigate coupling interactions that often emerge in systems exceeding 100 qubits, the company refined its tunable coupler designs, shifting the primary performance constraints toward coherence times. For quantum error correction (QEC) research, the system utilizes adiabatic CZ gates. Rigetti’s internal benchmarks on prototype systems have demonstrated CZ gate fidelities as high as 99.9% at 28 nanoseconds, and these gate schemes are currently being integrated into the 108-qubit production environment. The availability of these high-fidelity native gates is intended to allow researchers to compile more efficient circuits for surface code and other error-correcting protocols. According to Amazon Braket, the addition of the Cepheus-1-108Q provides a third generation of Rigetti hardware on the platform, following the Aspen and Ankaa series. The increased qubit count is aimed at users performing research in materials science, optimization, and quantum simulation who require wider and deeper circuit execution than was available on previous 36-qubit systems. The integration supports standard quantum assembly languages and OpenQASM 3.0 for circuit submission. Rigetti’s current technical roadmap targets a median two-qubit gate fidelity of 99.5% for the Cepheus-1-108Q later in 2026. The company intends to provide a formal roadmap update in the second half of the year, which will outline the engineering steps planned to reach quantum advantage within approximately three years. Future development will focus on innovations in materials and fabrication to address the coherence limitations identified during the scaling of this 108-qubit system. For the technical specifications and availability details regarding the 108-qubit system, consult the official Rigetti news release here. The integration details for Amazon Braket are available through AWS here, while the Quantum Computing Report provides context on the updated release timeline here. April 7, 2026 Mohamed Abdel-Kareem2026-04-07T17:52:32-07:00 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.