Scientists Achieve Coulomb Crystallization of Xenon Highly Charged Ions in Laser-Cooled Calcium Matrix
Researchers have successfully sympathetically cooled and crystallized highly charged xenon ions (HCIs) by embedding them within laser-cooled calcium ion (Ca⁺) Coulomb crystals inside a cryogenic linear Paul trap. The HCIs were produced in a compact electron beam ion trap, charge-selected, decelerated, and injected into the trap, where they appear as dark voids in fluorescence images. This platform opens new avenues for optical frequency metrology, searches for physics beyond the Standard Model, and quantum information science.
A multinational team of physicists reports the sympathetic cooling and Coulomb crystallization of xenon highly charged ions (HCIs) co-trapped with laser-cooled ⁴⁰Ca⁺ ions in a cryogenic linear Paul trap. The xenon HCIs were generated in a compact electron beam ion trap, then charge-selected, decelerated, and injected into the Paul trap, where they were captured into pre-formed Ca⁺ Coulomb crystals and appear as dark voids in fluorescence images due to their lack of laser-accessible transitions. Fine control over ion numbers enabled the realization of mixed-species crystals with arbitrary ordering patterns, and studies of Xe^(q+)–Ca⁺ strings allowed confirmation of HCI charge states, measurement of their lifetimes, and characterization of mixed-species motional modes. The system effectively merges the well-developed quantum control toolbox of Ca⁺ with the rich atomic structure of xenon HCIs, which feature highly sensitive transitions useful for precision measurement. The work was published in Physical Review A (2026) and represents a significant step toward using HCIs as probes for new physics, including tests of quantum electrodynamics and searches for dark matter or variation of fundamental constants.
What's missing
Systematic frequency metrology or new-physics search results are not yet reported.
What different sources said
- arXiv physicsCenter
Coulomb crystallization of xenon highly charged ions in a laser-cooled Ca+ matrix
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