Rigetti Unveils Breakthrough Chip Fabrication Process for Scalable QPUs

Rigetti Computing, a pioneer in full-stack quantum-classical computing, has introduced a novel chip fabrication process called Alternating-Bias Assisted Annealing (ABAA) that enables more precise qubit frequency targeting and improved execution of 2-qubit gates. This breakthrough technique, recently published in Nature Communications Materials, allows for higher fidelity and reduced defects in superconducting qubits.

The ABAA process involves applying low, alternating voltages to the oxide barrier at room temperature, precisely tuning qubit frequencies prior to chip packaging. This innovation is crucial for large-scale QPU production, improving addressability, speeding up interactions, and enhancing scalability. Dr. Subodh Kulkarni, Rigetti’s CEO, believes this technique strengthens their path to scaling higher qubit count systems with greater control over qubit performance. The company will leverage ABAA for its anticipated 84-qubit Ankaa-3 system, expected to be deployed by the end of 2024.

Novel Chip Fabrication Process for Scalable Quantum Computing

Rigetti Computing, Inc., a pioneer in full-stack quantum-classical computing, has introduced a novel chip fabrication process called Alternating-Bias Assisted Annealing (ABAA). This technique 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. The ABAA process was recently published in Nature Communications Materials.

The ABAA technique is based on the application of low, alternating voltages at room temperature to the oxide barrier in Josephson Junctions (JJs), which are the basis of Rigetti’s superconducting qubits. This approach enables precise control over qubit frequencies, allowing for improved addressability and scalability of the technology. Unlike more complicated solutions that 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.

The ability to controllably tune qubits prior to packaging is essential for large-scale QPU production. The ABAA technique improves the precision and accuracy of Rigetti’s qubits, allowing for clearer communication between qubits and couplers, which leads to improved performance due to less interference on the circuit. This novel process has also proven to heal some of the defects and imperfections in the JJs, further contributing to higher fidelity.

Improving Qubit Performance with ABAA

The ABAA technique is a significant advancement in the field of quantum computing, as it addresses the long-standing problem of junction reproducibility in superconducting qubits. By applying alternating voltages to the oxide barrier, Rigetti researchers have demonstrated precise control over qubit frequencies, enabling improved execution of 2-qubit gates and reduction in defects.

The simplicity and scalability of the ABAA process make it an attractive solution for large-scale QPU production. Unlike more complicated techniques that require laser trimming of the chip, the ABAA technique is a straightforward and cost-effective approach that can be easily integrated into existing fabrication processes. This novel process has the potential to significantly improve the performance and scalability of quantum computing systems.

Scalability and Control with ABAA

The ABAA technique is essential for large-scale QPU production, as it enables precise control over qubit frequencies prior to packaging. This approach improves the addressability of the qubits, speeds up interactions, and enhances the scalability of the technology. By leveraging the ABAA process, Rigetti aims to scale its quantum computing systems to even higher qubit counts with greater control over qubit performance.

The Company’s anticipated 84-qubit Ankaa-3 system, expected to be deployed by the end of 2024, will leverage the ABAA technique to improve qubit performance and scalability. This novel process has the potential to significantly advance the field of quantum computing, enabling more powerful and reliable systems that can tackle complex problems in fields such as chemistry, materials science, and optimization.

Rigetti’s Full-Stack Quantum Computing Approach

Rigetti is a pioneer in full-stack quantum-classical computing, with a proprietary quantum-classical infrastructure that provides high-performance integration with public and private clouds for practical quantum computing. The Company has operated quantum computers over the cloud since 2017 and serves global enterprise, government, and research clients through its Rigetti Quantum Cloud Services platform.

Rigetti’s full-stack approach encompasses chip design and fabrication, as well as software development and cloud services. The Company designs and manufactures its chips in-house at Fab-1, the industry’s first dedicated and integrated quantum device manufacturing facility. This vertical integration enables Rigetti to rapidly test and implement new methods to improve its qubit performance and scalability.

By leveraging its full-stack approach and novel processes like ABAA, Rigetti is well-positioned to advance the field of quantum computing and provide more powerful and reliable systems for its clients.