World’s First Working Nuclear Clocks

• 12 Oct 2026

Recently, two independent research groups one led by TU Wien (Vienna, Europe) and the other by Tsinghua University (Beijing, China) published studies about the world's first operational nuclear clocks.

What are Nuclear Clocks?

• Nuclear clocks are ultra-precise timekeeping devices that measure time using transitions in an atom’s nucleus rather than the movement of its electrons, as in conventional atomic clocks.
• Thorium-229 is particularly suitable because of its unusually low-energy nuclear transition, which can be excited using a laser.

Working Principle

• Laser Excitation: A laser stimulates the thorium-229 nucleus into a higher-energy state.
• Signal Detection: Scientists measure the signal associated with the nucleus returning to its original state.
• Frequency Reference: This nuclear transition provides a highly stable frequency reference for precise time measurement.

Potential Applications

• Navigation: Could improve the precision of Global Positioning System (GPS) and other navigation systems.
• Scientific Research: May enable more sensitive tests of fundamental physical laws and improve understanding of the universe.
• Strategic Applications: Could strengthen timekeeping for defence, financial networks and space missions.
• Quantum Technology: May open new avenues in precision measurement and quantum physics.