Overview
- The Centre for Quantum Technologies team published results on 23 September showing two lutetium ion optical clocks whose ticks matched to the 19th decimal.
- The group reports a measured frequency uncertainty of 1×10⁻¹⁹, a claimed fourfold improvement over the previous record and the lowest uncertainty published for an optical clock.
- The team verified accuracy by building two independent Lu+ clocks and comparing them over about 200 hours using long-duration correlation spectroscopy, producing the most precise clock-to-clock comparison so far.
- Lutetium offers practical advantages because its clock transition is far less sensitive to temperature and magnetic-field shifts, and the system runs at room temperature with commercial lasers, which supports plans to miniaturize and make transportable versions.
- Clocks at the 10⁻¹⁹ level detect gravitational time dilation over millimetres, which complicates inter-laboratory benchmarks and is now a key challenge for international bodies that are assessing optical-clock data for a possible redefinition of the second around or after 2030.