Related Experiment Video
Updated: Sep 18, 2025
10:42
Preparing an Isotopically Pure 229Th Ion Beam for Studies of 229mTh
Published on: May 3, 2019
6.9K
Design of new thorium nuclear clock materials based on polyatomic ions
Harry W T Morgan1,2, Hoang Bao Tran Tan3,4, Andrei Derevianko3
1Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E Young Drive, Los Angeles, California 90095, USA. harry.morgan@manchester.ac.uk.
Dalton Transactions (Cambridge, England : 2003)
|June 20, 2025
Summary
Researchers explored new host materials for thorium (Th) nuclear clocks. Salts with superhalogen anions, like M(BF4)2, show promise for wider band gaps, while MSO4 may offer improved clock accuracy by reducing nuclear spin interference.
Area of Science:
- Solid-state physics
- Quantum optics
- Materials science
Background:
- The 229Th nucleus has a unique low-energy excited state suitable for ultra-precise nuclear clocks.
- Host materials are crucial for stabilizing the 229Th nucleus, requiring band gaps exceeding the nuclear transition frequency.
- Existing fluoride hosts face limitations due to nuclear spin interactions and bonding constraints.
Purpose of the Study:
- To theoretically investigate novel host materials for 229Th nuclear clocks using superhalogen anions.
- To identify candidate materials with suitable electronic properties for hosting 229Th.
- To explore anions that can mitigate detrimental nuclear spin couplings.
Main Methods:
- Computational investigation of electronic properties for Ca, Sr, and Ba compounds with BF4-, ClO4-, and SO4(2-) anions.
- Calculation of band gaps and analysis of ionic bonding characteristics.
- Assessment of potential nuclear spin interactions in host materials.
Main Results:
- M(BF4)2 compounds exhibit the widest band gaps, indicating suitability for hosting 229Th.
- MSO4 compounds show potential for high-accuracy clocks by minimizing inhomogeneous broadening from nuclear spins.
- Superhalogen anions offer a route to push ionic bonding limits and explore new host materials.
Conclusions:
- Compounds containing BF4- anions are promising candidates for 229Th clock hosts due to their large band gaps.
- Compounds with SO4(2-) anions may lead to more accurate nuclear clocks by suppressing nuclear spin decoherence.
- This study provides guidance for experimental searches for advanced 229Th clock materials.
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