Quantinuum Helios: 48 Logical Qubits at 2:1 Overhead
In November 2025, Quantinuum commercially launched Helios, its next-generation trapped-ion quantum computer. Using 98 physical qubits in a volume ion trap architecture, Helios achieved 48 error-corrected logical qubits — a physical-to-logical overhead ratio of approximately 2:1.
This milestone represents a qualitative leap beyond previous records. Earlier, the collaboration with Microsoft on H2 had demonstrated 12 logical qubits from 56 physical qubits (4.6:1 ratio). Helios slashes that overhead to near parity, while establishing new fidelity benchmarks: 2Q gate fidelity of 99.921%, 1Q gate fidelity of 99.9975%, and logical SPAM fidelity of 99.99%.
Helios also introduced the first commercial use of an ion junction, enabling volume-to-volume ion transfer — a key step toward scalable fault-tolerant architectures. Quantinuum's roadmap continues toward Sol (2027) and Apollo (2029), targeting hundreds of logical qubits.