Speaker
Description
The $g$ factor of the bound electron in few-electron highly charged ions is a highly sensitive probe for new physics and its measurement allows to test the predictions of quantum electrodynamics (QED) in the extremely strong electric field of the nucleus. Studying these simple atomic systems allows to examine bound-state QED and even nuclear effects to high accuracy. ALPHATRAP [1] is a cryogenic Penning-trap apparatus for high-precision $g$-factor measurements. By confining single ions in ultra-stable electromagnetic fields, the $g$-factor can be determined at the sub-ppb level [2].
Here, I will present the results of recent $g$-factor measurements at ALPHATRAP as well as the future plans on an even more precise measurement on $^{12}$C$^{5+}$ and $^{14}$C$^{5+}$.
[1] S. Sturm, et al. Eur. Phys. J. Spec. Top. 227, 1425-1491 (2019).
[2] J. Morgner, et al. Nature 622, 53–57 (2023).