Key Points:
- Physicists measured thorium-229’s energy transition frequency with unprecedented accuracy, paving the way for nuclear clocks.
- Nuclear clocks could surpass atomic clocks in precision and stability, opening new avenues in fundamental physics, including dark matter research.
- A frequency comb laser system was used to achieve the precise measurement, marking a significant technological leap.
- Further improvements are needed in laser technology and thorium-229 configurations to enhance the accuracy and practicality of nuclear clocks.
In recent research, Physicists have demonstrated the key components of a nuclear clock, which could revolutionize precision measurements and offer new insights into fundamental physics. Led by Jun Ye at JILA in Boulder, Colorado, researchers measured the frequency of light that prompts thorium-229 nuclei to shift to a higher energy state—marking the ‘tick’ of the nuclear clock—with 100,000 times greater accuracy than previous attempts. This breakthrough, published in Nature, utilized a frequency comb laser system synchronized with the world’s most accurate atomic clocks.
While not yet a fully operational clock, this progress indicates the feasibility of nuclear clocks, which would track time using energy transitions within atomic nuclei rather than electrons. Unlike atomic clocks, which are accurate to within one second every 40 billion years, nuclear clocks could achieve even greater precision and stability due to the reduced sensitivity of nuclear particles to environmental disturbances.
The development of the clocks could have significant implications for particle physics, potentially revealing interactions with dark matter. The clock’s tick rate, set by nuclear forces, provides a unique window into these forces, which could help identify if dark matter affects them on a microscopic scale. Such sensitivity could be 100 million times greater than atomic clocks, making nuclear clocks powerful tools for exploring fundamental forces.
The researchers used a frequency comb to probe trillions of thorium-229 nuclei embedded in a crystal, enabling them to identify the transition frequency with unprecedented precision. This frequency was found by illuminating the crystal with a range of laser frequencies, allowing for simultaneous testing rather than sequential scanning.
While nuclear clocks are not yet as precise as atomic clocks, further advancements in laser technology and experimentation with thorium-229 configurations could close the gap. The research team is optimistic about the future potential of these timekeepers, which could redefine precision standards in both timekeeping and fundamental physics research.
