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Rigetti Introduces Novel Chip Fabrication Process For Scalable, High Performing QPUs
Rigetti’s novel technique, Alternating-Bias Assisted Annealing (ABAA), allows for more precise qubit frequency targeting, enabling improved execution of
About this update from Rigetti Computing, Inc.
[{"type":"text","content":"Rigetti’s novel technique, Alternating-Bias Assisted Annealing (ABAA), allows for more precise qubit frequency targeting, enabling improved execution of 2-qubit gates and a reduction in defects, which both contribute to higher fidelity. This work was recently published in Nature Communications Materials. BERKELEY, Calif., Aug. 15, 2024 (GLOBE NEWSWIRE) -- Rigetti Computing, Inc. (Nasdaq: RGTI) (“Rigetti” or the “Company”), a pioneer in full-stack quantum-classical computing, today announced that its paper introducing a novel chip fabrication process, Alternating-Bias Assisted Annealing (ABAA), was recently published in Nature Communications Materials. ABAA allows for more precise qubit frequency targeting, enabling improved execution of 2-qubit gates and improvement in performance, which both contribute to higher fidelity. This technique is now being leveraged to fabricate chips for Rigetti QPUs, including the Novera™ QPU and the upcoming Ankaa™-3 system. The basis of Rigetti’s superconducting qubits are Josephson Junctions (JJs), which are two thin layers of superconducting metal (aluminum) separated by a barrier (aluminum oxide). Electrons are able to tunnel across the insulator from one electrode to another — resulting in a characteristic frequency for the qubit that allows for it to be controlled and measured. While the reproducibility and energy loss in these junctions has been difficult to control, the simplicity, scalability, and ease of fabrication of these superconducting devices makes them one of the most desirable platforms for building quantum computers. Finding a solution to the junction reproducibility problem has been a long-standing goal in the field. Rigetti researchers discovered that by applying a series of low, alternating voltages at room temperature to the oxide barrier, the qubit frequencies can be precisely targeted. The ability to controllably tune qubits prior to a chip being packaged is essential for large-scale QPU production. This improves the addressability of the qubits, speeds up interactions, and improves the scalability of the technology. Unlike more complicated solutions that address the problem of tuning frequency, which often require laser trimming of the chip, the ABAA technique is a simple and scalable process that only requires sending pulses of voltage to the chip. “We’ve long known that ...