Quantum electrodynamics (QED) is a quantum field theory that describes the interaction between light and matter, and is also the best quantum theory in modern physics. However, this statement is mainly based on extremely precise research in the fields of relatively low field strength and lighter atoms and ions. In the field of very strong electromagnetic fields, such as in the heaviest highly charged ions (with a nuclear charge Z ≫ 1), quantum electrodynamics QED calculations enter non perturbative states with different properties. However, the corresponding experimental research is very challenging, and theoretical predictions are only partially tested.
Recently, R. Loetzsch from Friedrich Schiller Universit ä t in Germany and M. Trassinelli from Sorbonne Universit é in France published a series of experiments in Nature to detect high-order quantum electrodynamics QED effects and electron electron interactions in high-Z regions. This is mainly achieved through the multi reference method of Doppler tuned X-ray emission, which detects relativistic uranium ions with different charge states.
The heaviest double electron ion (U90+) has an intra shell transition energy with an accuracy of 37ppm. In addition, uranium ions with different numbers of bound electrons were compared to unlock and test the single electron high-order quantum electrodynamics QED effect and bound electron electron interaction term separately, without uncertainty related to nuclear radius. The experimental results can distinguish several state-of-the-art theoretical methods and provide important benchmarks for strong field calculations.
Figure 1: Experimental setup
Figure 2: Experimental and theoretical values of intra shell transitions
Figure 3: Experimental sensitivity to theoretical contributions
Editor:Sichuan Jinzhongde Science and Technology Research Institute
Source: Today's New Materials
