Scientists have demonstrated for the first time that experimental nuclear clocks can be used in practice to measure time, according to research published on October 7 in the journal Nature. The achievement, led by a joint team from Europe and China, could pave the way for more precise timekeeping and new tests of fundamental physics.

Key Takeaways

• Nuclear clocks have been shown to work in practice for time measurement for the first time.
• The research was published on October 7 in the journal Nature by a joint European-Chinese team.
• Participants included researchers from Vienna University of Technology, Germany’s national institute for measurement, and China’s Tsinghua University.
• Unlike atomic clocks that use electron transitions, nuclear clocks rely on energy transitions in an atom’s nucleus.
• Both experimental clocks use the isotope thorium-229 embedded in calcium fluoride, triggered by a special ultraviolet laser.

How Nuclear Clocks Differ from Atomic Clocks

Traditional atomic clocks measure time by tracking energy transitions in an atom’s electrons. The new nuclear clocks instead operate based on energy transitions occurring in the atom’s nucleus, offering a fundamentally different physical reference.

According to the scientists, this method could serve as the foundation for developing a more stable and sensitive system for measuring time.

The Thorium-229 Approach

Both experimental clocks are based on an isotope named thorium-229, which was incorporated into a calcium fluoride material. A special ultraviolet laser triggers the energy transition in its nucleus, while the nucleus provides a reference to keep the laser’s frequency stable.

Research Collaboration

The work involved researchers from Vienna University of Technology, Germany’s national institute for measurement, and China’s Tsinghua University. Their joint effort marks the first practical demonstration of nuclear clocks for time measurement.

Performance and Outlook

Although these initial prototypes have not yet reached the performance of the best optical atomic clocks, according to the researchers, this achievement provides an important foundation for further improving this technology. The team’s findings suggest that nuclear clocks could play a significant role in making time measurement more precise in the future and in researching fundamental principles of physics.

Why It Matters

The demonstration opens a new path for timekeeping that could eventually surpass existing atomic clock technology. By using nuclear transitions, these clocks may offer greater stability and sensitivity, which could benefit both practical time measurement and fundamental physics research.