Journal article

Publication year: 2024

Journal: Nature

Volume number: 625

Issue number: 7996

ISSN: 0028-0836

eISSN: 1476-4687

Open access status: Hybrid

DOI Link: https://doi.org/10.1038/s41586-023-06910-y

Publisher: Nature Research

Abstract: 

Quantum electrodynamics (QED), the quantum field theory that describes the interaction between light and matter, is commonly regarded as the best-tested quantum theory in modern physics. However, this claim is mostly based on extremely precise studies performed in the domain of relatively low field strengths and light atoms and ions1-6. In the realm of very strong electromagnetic fields such as in the heaviest highly charged ions (with nuclear charge Z >> 1), QED calculations enter a qualitatively different, non-perturbative regime. Yet, the corresponding experimental studies are very challenging, and theoretical predictions are only partially tested. Here we present an experiment sensitive to higher-order QED effects and electron-electron interactions in the high-Z regime. This is achieved by using a multi-reference method based on Doppler-tuned X-ray emission from stored relativistic uranium ions with different charge states. The energy of the 1s1/22p3/2 J = 2 -> 1s1/22s1/2 J = 1 intrashell transition in the heaviest two-electron ion (U90+) is obtained with an accuracy of 37 ppm. Furthermore, a comparison of uranium ions with different numbers of bound electrons enables us to disentangle and to test separately the one-electron higher-order QED effects and the bound electron-electron interaction terms without the uncertainty related to the nuclear radius. Moreover, our experimental result can discriminate between several state-of-the-art theoretical approaches and provides an important benchmark for calculations in the strong-field domain.

An experiment sensitive to higher-order quantum electrodynamics effects and electron-electron interactions in the high-Z regime was performed using a multi-reference method based on Doppler-tuned X-ray emission from stored relativistic uranium ions with different charge states.

Harvard Citation style: Loetzsch, R., Beyer, H., Duval, L., Spillmann, U., Banas, D., Dergham, P., et al. (2024) Testing quantum electrodynamics in extreme fields using helium-like uranium, Nature, 625(7996). https://doi.org/10.1038/s41586-023-06910-y

APA Citation style: Loetzsch, R., Beyer, H., Duval, L., Spillmann, U., Banas, D., Dergham, P., Kroeger, F., Glorius, J., Grisenti, R., Guerra, M., Gumberidze, A., Hess, R., Hillenbrand, P., Indelicato, P., Jagodzinski, P., Lamour, E., Lorentz, B., Litvinov, S., Litvinov, Y., ...Trassinelli, M. (2024). Testing quantum electrodynamics in extreme fields using helium-like uranium. Nature. 625(7996). https://doi.org/10.1038/s41586-023-06910-y