Singapore Scientists Build World's Most Accurate Lutetium Atomic Clock

Researchers at NUS's Centre for Quantum Technologies built an optical atomic clock using a lutetium-176 ion with an uncertainty of 1 × 10⁻¹⁹, the lowest reported for any optical clock. Two such clocks agreed to within 5.7 × 10⁻¹⁹ over 200 hours, enough to detect a 5 mm height difference.

• Transition frequency measured to 19 decimal places with uncertainty of 1 × 10⁻¹⁹
• Two lutetium clocks agreed to 5.7 × 10⁻¹⁹ over 200 hours of comparison
• Clocks can resolve a 5 mm height difference via gravitational time dilation
• Lutetium's transition is barely affected by temperature and magnetic fields