10094265Full-Stack Superconducting 24-Qubit Quantum Computing Testbed With Tunable Couplers and Scalable Control SystemClosedSmall Business Research InitiativeInnovate UKRigetti proposes delivering a 24-qubit quantum computing system based on its fourth-generation architecture at the NQCC facility on Harwell Campus. In this project, Riverlane also will develop proprietary digital control interfaces for superconducting Quantum Processing Units (QPUs) and integrate them with Rigetti's system. The proposed 24-qubit quantum computer will feature Rigetti's fourth-generation QPUs, the basis of its US-based 84-qubit quantum computer, expected to be available publicly at the end of 2023 and currently internally deployed for R&D and to select partners. The architecture features tunable couplers and a square lattice, which enables faster gate times, higher fidelity, and greater connectivity compared to Rigetti's previous generations of QPUs. Rigetti's full stack, including custom-built control systems and Rigetti QCS (Quantum Cloud Services), will be deployed, offering users the opportunity to harness the full spectrum of the quantum computer's capabilities. Rigetti's software development framework includes proprietary tools such as pyQuil, enabling the creation and execution of quantum computing algorithms, the Quilc compiler, and Quil-T for pulse-level access. Concurrently with Rigetti's testbed implementation, Riverlane will deliver the Quantum Error Correction (QEC) stack, Deltaflow, which allows execution of error-correction experiments using Riverlane’s fast and accurate decoders. Deltaflow communicates with the quantum computers through a universal QEC Interface, enabling flexible upgrading and scaling up of the decoders and the control systems.