Rigetti Computing, Inc. which is developing quantum computers based on superconducting qubits, announced on January 9 that it has postponed the launch of its Cepheus™-1-108Q system from end-2025 to the end of Q1 2026.
According to Rigetti CEO Dr. Subodh Kulkarni, the delay is caused by complexities with the system’s tunable couplers, stalling the chip’s ability to achieve the promised 99.5% median two-qubit gate fidelity.
“While we are making strong progress with Cepheus-1-108Q, we are taking more time to test and optimize the system to ensure the performance is up to our standards,” says Rigetti CEO Dr. Subodh Kulkarni. “We have a clear understanding of what we need to do to achieve 99.5% median two-qubit gate fidelity, and are well on our way. Building higher qubit count systems can uncover new challenges. We encountered complexities with our tunable couplers and have decided to run another iteration of our chip to further optimize the system and improve fidelity.”
“We continue to improve our system performance, achieving a median two-qubit gate fidelity of 99% on our 108-qubit system, 99.7% on our 9-qubit system, and 99.6% on our 36-qubit system. This underscores our unwavering commitment to delivering the highest performing systems for our partners and customers.”
Rigetti’s quantum systems are based on a modular architecture that tiles twelve 9-qubit chiplets together. The predecessor of the upcoming Cepheus-1-108Q, named Cepheus-1-36Q, was made available in mid-2025 and consists of four chiplets. Ultimately, the company hopes to produce a 1000-qubit system by 2027.
