JILA researchers are pioneering a nuclear clock using thorium-229, which offers unprecedented stability compared to atomic clocks.

By embedding thorium into a solid-state crystal, they have found a nuclear transition largely resistant to temperature changes, crucial for precision timekeeping. Their work could not only redefine timekeeping but also open doors to detecting new physics.

Pushing Beyond Atomic Clocks For decades, atomic clocks have set the standard for precision timekeeping, playing a crucial role in GPS navigation, physics research, and fundamental scientific tests. Now, researchers at JILA, led by physics professor Jun Ye in collaboration with the Technical University of Vienna, are exploring an even more stable alternative: a nuclear clock. Unlike atomic clocks, which rely on electron transitions, this new clock is based on a low-energy transition within the nucleus of a thorium-229 atom. Because nuclear transitions are less affected by environmental disturbances, a thorium-based clock could offer unprecedented stability and be used to test physics beyond the Standard Model.