19–22 Jan 2026
CERN
Europe/Zurich timezone

Coherent spectroscopy with a single antiproton spin for the antiproton magnetic moment measurements in BASE

21 Jan 2026, 11:30
15m
503/1-001 - Council Chamber (CERN)

503/1-001 - Council Chamber

CERN

162
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Speaker

Dr Barbara Maria Latacz (CERN)

Description

BASE - The Baryon-Antibaryon Symmetry Experiment - is dedicated to conduct ultra-precise tests of Charge Parity Time reversal invariance by comparing key intrinsic properties of protons and antiprotons, such as their charge-to-mass ratios, lifetimes, and magnetic moments.
In this presentation, we will highlight our flagship experiment at CERN, which is currently focused on achieving 10- to 100-fold improved measurements of proton and antiproton magnetic moments. To date, we have determined these quantities with fractional uncertainties of 1.5 parts per billion [1] for the antiproton and 300 parts per trillion [2] for the proton.
Recent progress has been driven by major technical upgrades, including the implementation of a superconducting shielding and shimming system and a newly developed cooling trap [3] that provides vastly enhanced cyclotron-mode cooling performance. These advances have enabled 100%-fidelity, non-destructive spin-state spectroscopy of single antiprotons [3]. In this significant experimental upgrade, we successfully suppressed numerous decoherence mechanisms, culminating in the first non-destructive coherent spectroscopy of a single antiproton spin. In these experiments we have achieved a spin coherence time of 50 seconds, and full control over the linewidth of the g-factor resonance. Using coherence times of 10 s we achieved a sixteenfold reduction in spectral linewidth compared to previous measurements. This represents the first demonstration of an antimatter quantum bit (qubit) and paves the way for much more precise comparisons between the behavior of matter and antimatter.
We will present the recently published results on coherent antiproton spin spectroscopy and discuss ongoing efforts aimed at further improving the precision of both antiproton and proton magnetic moment measurements.
1. C. Smorra, et al., Nature 550.7676 (2017): 371-374.
2. G. Schneider, et al., Science 358.6366 (2017): 1081-1084
3. B. M. Latacz, et al., Phys. Rev. Lett. 133.5 (2024): 053201
4. B. M. Latacz, er al., Nature 644, 64–68 (2025)

Topic Experiments

Authors

Dr Barbara Maria Latacz (CERN) Prof. Stefan Ulmer (HHU Düsseldorf / RIKEN)

Co-authors

Andreas Mooser Ann Maria Thomas (Heinrich Heine University Dusseldorf (DE)) Anna Soter (ETH Zürich) Bela Peter Arndt (Max Planck Society (DE)) Christian Ospelkaus (Leibniz Universitaet Hannover (DE)) Christian Smorra (Heinrich Heine University Dusseldorf (DE)) Daniel Schweitzer Popper (Heinrich Heine University Dusseldorf (DE)) Frederik Völksen Hüseyin Yildiz (Johannes Gutenberg-Universität Mainz) Jack Devlin Jochen Walz (Johannes Gutenberg Universitaet Mainz (DE)) Jonathan Morgner (Universitaet Hannover (DE)) Klaus Blaum (Max Planck Society (DE)) Louis Constantin Freymann (Max Planck Society (DE)) Marcel Leonhardt (Heinrich Heine University Dusseldorf (DE)) Peter Micke Raphael Paul Czampiel (Heinrich Heine University Dusseldorf (DE)) Satoshi Endoh (University of Tokyo (JP)) Simon Stahl (Leibniz Universitaet Hannover (DE)) Tomoka Imamura (Physikalisch-Technische Bundesanstalt(DE)) Wolfgang Quint Yasunori Yamazaki (-) Yasuyuki Matsuda (University of Tokyo (JP))

Presentation materials