Quantum Computing
Evergreen explainer · neutral data, no opinion

Best 2-qubit gate fidelity

Current verified value
99.99%
IonQ · trapped ion — first “four nines” (2025)
Press release · 2025-10 Human-verified

What it measures

How often a two-qubit operation succeeds. The threshold for practical error correction sits around 99.9% (“three nines”).

Glossary →

History

100.05%99.90%99.75%99.59%99.44%EC threshold ≈ 99.9%20232024-122025-11

By actor

IonQtrapped ion, EQC (2025)99.99%
Quantinuumtrapped ion, Helios (2025)99.92%

Goal / baseline

now99.99%
goal99.99%
baselineEC threshold ≈ 99.9%

“four nines” — comfortable fault tolerance

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