Laser Spectroscopy of Triply Charged 229Th Isomer Reveals Key Parameters for a Nuclear Clock

Core Concepts

Laser spectroscopic study of the triply charged 229Th isomer (229mTh3+) provides essential parameters for developing a highly accurate nuclear clock based on the 229Th nuclear transition.

Abstract

The content discusses the potential of using the optical nuclear transition in thorium-229 (229Th) for developing a nuclear clock that could surpass the accuracy of existing atomic clocks. Specifically, it focuses on the triply charged 229Th (229Th3+) as the most suitable charge state for a nuclear clock due to its closed electronic transitions, which enable laser cooling, laser-induced fluorescence detection, and state preparation of ions.
The key highlights and insights from the content are:

The authors report the trapping of the 229Th isomer (229mTh3+) continuously supplied by a 233U source and the determination of its nuclear decay half-life to be 1,400(+600/-300) seconds through nuclear-state-selective laser spectroscopy.

By determining the hyperfine constants of 229mTh3+, the authors were able to reduce the uncertainty of the sensitivity of the 229Th nuclear clock to variations in the fine-structure constant by a factor of four.

These results provide essential parameters for the development of the 229Th3+ nuclear clock and its potential applications in the search for new physics.

Stats

The nuclear decay half-life of the isolated 229mTh3+ was determined to be 1,400(+600/-300) seconds.

Quotes

"A nuclear clock based on this nuclear-transition frequency is expected to surpass existing atomic clocks owing to its insusceptibility to surrounding fields."
"Furthermore, by determining the hyperfine constants of 229mTh3+, we reduced the uncertainty of the sensitivity of the 229Th nuclear clock to variations in the fine-structure constant by a factor of four."

Key Insights Distilled From

Laser spectroscopy of triply charged 229Th isomer for a nuclear clock - Nature

by Atsushi Yama... at www.nature.com 04-17-2024

https://www.nature.com/articles/s41586-024-07296-1

Deeper Inquiries

What other potential applications of the 229Th nuclear clock, beyond the search for new physics, could be explored

The 229Th nuclear clock holds promise for various applications beyond the realm of fundamental physics. One significant area is in geodesy and navigation systems, where ultra-precise timekeeping is crucial for satellite-based positioning and timing. The stability and accuracy offered by the 229Th nuclear clock could enhance global navigation systems, enabling more precise positioning and synchronization for applications such as GPS and geodetic surveys. Additionally, the clock's insensitivity to external perturbations makes it valuable for synchronization in distributed sensor networks, communication systems, and secure data transmission, where precise timing is essential for coordination and data integrity.

How might the findings from this study be used to address the technical challenges in the development of a practical 229Th nuclear clock

The findings from this study provide crucial insights into the properties of triply charged 229Th ions, particularly the nuclear decay lifetime and hyperfine constants of the isomeric state. These parameters are essential for optimizing the operation of a practical 229Th nuclear clock. By accurately determining the nuclear decay half-life of 229mTh3+ and the hyperfine constants, researchers can refine the clock's frequency stability and reduce uncertainties associated with environmental factors. This knowledge can guide the design of laser systems for state manipulation and detection, as well as aid in the development of trapping and cooling techniques for 229Th ions. Ultimately, the precise characterization of 229mTh3+ properties enhances the feasibility of constructing a robust and accurate 229Th nuclear clock.

What other nuclear transitions or isotopes could be investigated for the development of even more accurate nuclear clocks in the future

In the pursuit of advancing nuclear clock technology, researchers may explore other nuclear transitions and isotopes with favorable properties for timekeeping applications. One promising avenue is the investigation of thorium isotopes beyond 229Th, such as thorium-230 or thorium-228, which may exhibit unique nuclear transitions suitable for high-precision clocks. Additionally, isotopes of other elements like uranium, radium, or actinium could be studied for their nuclear properties that could lead to enhanced clock performance. Exploring exotic nuclear transitions in rare isotopes or isomeric states of different elements could unlock new possibilities for developing even more accurate and stable nuclear clocks in the future.