Physicists Built Most Accurate Lutetium Atomic Clocks
The clocks reached a record-low error estimate, a milestone that could help redefine the international second by 2030.
Updated on Sept. 28, 2026 in Physics
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Researchers at the National University of Singapore have developed two atomic clocks using lutetium atoms that achieved an error estimate of 1 part in 10 quintillion. This represents the most accurate measurement reported to date, four times more precise than the previous record.
Why it matters
The development advances the precision required to redefine the global standard for the second, a change expected by international bodies in 2030 or later. Comparing two independent clocks is the only method to verify these standards, and this study provides a new performance benchmark for timekeeping.
The lutetium clocks achieved an error estimate of 1 part in 10 quintillion, while the two clocks agreed within 5.7 parts in 10 quintillion during a 200-hour test. This precision allowed researchers to measure the height difference between the two ions to within 1 millimeter.
The players
National University of Singapore
A research-intensive university in Singapore that hosts the Centre for Quantum Technologies and leads major initiatives in atomic physics and quantum sensing.
The details
The team achieved this accuracy by holding single lutetium ions, charged particles that have lost electrons, in place using electric fields. To cancel out experimental noise, researchers averaged three closely related ticks of the atom into one. Lutetium was chosen because it acts as the least sensitive established atomic clock system to environmental disturbances like heat and magnetic fields.
Timeline
The research team conducted 11 comparison runs over a 12-day period.
International standards organizations may redefine the second as early as 2030.
The Tech Race
This research provides a new high-water mark for accuracy in the global effort to improve optical atomic clocks. It follows a multi-year effort to surpass the precision of existing standards as researchers compete to provide the most stable timekeeping source for future SI unit redefinitions.
This development currently exists as a laboratory-scale experiment and has no immediate effect on consumer technology or commercial timekeeping. Future applications depend on the team successfully miniaturizing the system into a transportable unit for practical use.
The takeaway
The study demonstrates that lutetium is the most resilient candidate for next-generation timekeeping standards. Watch for future updates on the team's progress in miniaturizing these clocks into a transportable format, which is the necessary step for broader deployment.
Further reading
For more on the current state of measurement standards, see Physics.
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