MilestoneError correctionClaimed

Quantinuum says Helios kept an error-protected qubit at 99.9995% fidelity

Oct 19, 2026

On Oct. 19, 2026, Quantinuum reported that its Helios trapped-ion computer stored a logical qubit (an error-protected qubit built from many physical ones) with 99.9995% fidelity per error-correction round, about 5 failures per million. Errors fell 12-fold each time the code was made larger.

Why it matters

Errors that shrink as protection grows are the condition for scaling to fault-tolerant machines. Quantinuum, which calls it a record, says it supports its plan for Apollo in 2029.

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