Chinese Researchers Develop Thorium-229 Nuclear Optical Clock

People's Daily reported that a Chinese scientific research team has taken the lead internationally in developing a thorium-229 nuclear optical clock and achieving its stable operation. The corresponding research results were published online in the international academic journal Nature. Ding Shiqian, an associate professor in the Department of Physics at Tsinghua University and a corresponding author of the paper, explained that atomic optical clocks currently utilize electronic energy level transitions within atoms to provide precise time measurements. In contrast, the nuclear optical clock relies on nuclear energy level transitions inside the thorium-229 nucleus as a time and frequency reference, functioning like timekeeping through an internal nuclear rhythm. Because the physical scale of an atomic nucleus is far smaller than that of an entire atom, nuclear transitions experience significantly less disturbance from external electromagnetic environments. Ding Shiqian stated that, in principle, a nuclear optical clock can therefore provide a more precise time and frequency standard than existing atomic optical clocks. The research team stated that nuclear optical clocks are expected to serve as a new generation of time and frequency standards. Furthermore, solid-state nuclear optical clocks possess potential practical advantages for miniaturization and engineering implementation, providing viable technology options for high-precision time and frequency requirements in satellite navigation and deep space exploration scenarios.

The research team noted that nuclear optical clocks can provide a new precision detection platform for testing fundamental physical laws. In addition, the development opens new research directions for quantum precision measurement and quantum manipulation.