Record #00404Technology archive
Lowest Evaluated Systematic Fractional Uncertainty of an Optical Atomic Clock
A 2026 Nature study reported two lutetium-176 single-ion optical frequency references. Lu-1 achieved a reported evaluated fractional systematic frequency uncertainty of 1.2 × 10⁻¹⁹, while a separate same-species comparison independently tested the two references at a different precision.
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Current Record
1.2× 10⁻¹⁹
Current record value
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Overview
Archive NoteThe study used the atomic transition of trapped lutetium ions as optical frequency references, evaluating magnetic-field, blackbody-radiation and gravitational-redshift contributions to systematic uncertainty. The two independent clocks were evaluated at 1.2 × 10⁻¹⁹ and 1.3 × 10⁻¹⁹ respectively.
Correlation spectroscopy compared the two like-for-like clocks at an approximate statistical precision of 5.7 × 10⁻¹⁹. Evaluated single-clock systematic uncertainty and independently measured comparison precision are distinct quantities.
Record history
1 Milestones- 1.2 × 10⁻¹⁹Lu-1 lutetium-ion optical clockCurrent Record
Sources
Evidence & ReferencesVerification basis and limitations
Evidence-backedCredible sources support core facts; the comparison scope or corroboration remains incomplete.
Basis: corroborating reliable secondary materials
The October 2026 Nature primary paper evaluates Lu-1 at 1.2 × 10⁻¹⁹ and Lu-2 at 1.3 × 10⁻¹⁹ in fractional systematic uncertainty; its independent same-species comparison reaches 5.7 × 10⁻¹⁹ statistical precision. These are different uncertainty metrics, not interchangeable clock accuracy claims. The result is a reported leading evaluation rather than a universal ratification.
Comparison boundaries still under review
The 1.2 × 10⁻¹⁹ value is an evaluated fractional systematic-uncertainty budget for a specific single-ion reference, not a measured total timing error or the 5.7 × 10⁻¹⁹ comparison uncertainty. Other clock implementations have differing assumptions and evaluations.
- Verification assessment
- 2026-11-05
- Last editorial review
- 2026-11-05
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