Measurement of the g Factor of the Bound Electron in Hydrogen-like Oxygen 16O7+

The measurement of the g factor of the electron bound in a hydrogen-like ion is a high-accuracy test of the theory of Quantum Electrodynamics (QED) in strong fields. Here we report on the measurement of the g factor of the bound electron in hydrogen-like oxygen 16O7+. In our experiment a single 16O7+ ion is stored in a Penning trap. Quantum jumps between the two spin states (spin up and spin down) are induced by a microwave field at the spin precession frequency of the bound electron. The g factor of the bound electron is obtained by varying the microwave frequency and counting the number of spin flips. Our experimental value for the g factor of the bound electron is gexp(16O7+)=2.000 047 026(4). The theoretical prediction from non-perturbative bound-state QED calculations is gth(16O7+)=2.000 047 0202(6).