Atomic Quantum Chip Achieves 99.99% Fidelity in World-First

Researchers in Sydney have unveiled the world’s first scalable atomic quantum processor with record-high accuracy. By placing individual phosphorus atoms in silicon with extreme precision (“14/15” architecture), the team built a silicon quantum chip that reached 99.99% two-qubit fidelity – meaning nearly error-free operations. The prototype packs nine nuclear spin qubits and two atomic qubits linked across two clusters, demonstrating that multiple qubit clusters can work together on one chipl. Scientists say this unprecedented accuracy is a proof-of-concept toward fault-tolerant quantum computers with millions of qubits in the future. The achievement, published in Nature, suggests error-correction overhead could be dramatically reduced. “We have these long coherence times…and very little ‘bit flip’ errors… so the error correction codes are much smaller,” explained Michelle Simmons, CEO of Silicon Quantum Computing. In other words, their highly precise chip needs far fewer extra qubits for error fixing, freeing up more qubits for computation. This breakthrough brings quantum machines closer to practical usefulness, as ultra-high fidelity is crucial for scaling up to solve real-world problems