Underdog 'spin qubits' leap forward in race to a useful quantum computer

Research teams at HRL Laboratories in Malibu, California, and QuTech in Delft, the Netherlands, published papers in Nature on Monday describing silicon spin-qubit processors with error rates around 0.2%, Nature reported. HRL's processor included 18 spin qubits and QuTech's had 53, a leap from the two-qubit systems with 4% error rates that were state-of-the-art three years ago. Other groups are also advancing spin qubits. In April, Groove Quantum reported an 18-qubit germanium-based device with a similar error rate on the arXiv preprint server. Earlier this month, a group at RIKEN in Wako, Japan, reported a 5-qubit system with an error rate below 0.01% on a preprint server. Daniel Loss, a theoretical physicist at King Fahd University of Petroleum and Minerals, said the advancement is great for the community. Peer-review reports for the HRL paper called it a significant milestone in the technological maturity of semiconductor spin qubits. Superconducting-circuit quantum computers still operate with more than 100 qubits and neutral-atom systems have thousands, but the latest results show spin qubits can achieve comparable quality with low error. The results are a coup for HRL, which faced mass layoffs earlier this year after losing U.S. government contracts. Last week, IBM announced it would acquire HRL. Jay Gambetta, IBM's director of research, said in a statement that the HRL team will help IBM push even farther forward toward the frontiers of quantum innovation.