Speaker
Description
Recently, there has been impressive progress on the spectroscopy of molecular hydrogen ions, in both r.f. and Penning traps, at several laboratories (Paris, Zürich, Heidelberg, Amsterdam, Düsseldorf). This includes the first laser spectroscopy of H$_2^+$ [1, 2]. It is thus of interest to consider in more detail the proposals [3, 4] of comparing a vibrational transition frequency of H$_{2}^+$ with the analogous one in the antimatter molecule $\overline{\mathrm{H}}_2^-$. Such a comparison would offer a new opportunity to test CPT invariance, complementary to ongoing approaches. We have performed a detailed analysis of the proposal of Myers [4], to perform optical spectroscopy in a Penning trap with non-destructive read-out. This approach has recently been pioneered at ALPHATRAP [5,6]. We extend the analysis to Penning traps using quantum logic spectroscopy. We derive estimates for the achievable accuracy of the test. We find the level $1\times10^{-17}$ to be realistic, using technology mostly already available.
[1] M. R. Schenkel, S. Alighanbari, and S. Schiller, Laser spectroscopy of a rovibrational transition in the molecular hydrogen ion H$^+_
2$, Nature Physics 20, 383 (2024).
[2] S. Alighanbari, M. R. Schenkel, V. I. Korobov, and S. Schiller, High-accuracy laser spectroscopy of H$^+_2$ and the proton-electron mass ratio, Nature 664, 69 (2025).
[3] H. Dehmelt, Economic synthesis and precision spectroscopy of anti-molecular hydrogen ions in Paul trap, Physica Scripta T59, 423 (1995).
[4] E. G. Myers, CPT tests with the antihydrogen molecular ion, Phys. Rev. A 98, 010101 (2018).
[5] C. M. König, F. Heiße, J. Morgner, T. Sailer, B. Tu, D. Bakalov, K. Blaum, S. Schiller, and S. Sturm, Nondestructive Control of the Rovibrational Ground State of a Single Molecular Hydrogen Ion in a Penning Trap, Phys. Rev. Lett. 134, 163001 (2025)
[6] C. M. König et al., High-precision Penning-trap spectroscopy of the ground-state spin structure of HD$^+$, submitted (2025)
| Topic | Experiments |
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