Jacques Dupont‐Roc

Detection of very weak magnetic fields (10−9gauss) by 87Rb zero-field level crossing resonances

Zero-field level crossing resonances have been observed on the ground state of 87Rb. The width, a few microgauss, and the signal to noise ratio, about 2.5 × 103, allow the measurement of 10−9 gauss fields.

Lifting of a Zeeman degeneracy by interaction with a light beam

Abstract Observation on the ground state sublevels of an atom of light shifts much larger than the width of the levels is reported. The lifting of the Zeeman degeneracy in zero magnetic field by a light beam leads to a change in the Zeeman energy level diagram.

Physical interpretations for radiative corrections in the non-relativistic limit

A detailed physical discussion of the contribution of non-relativistic modes of the radiation field to electron radiative corrections (Lamb shift, g-2) is presented. It is shown that these corrections can be described by a simple effective Hamiltonian, derived from a single-particle theory, and that two main physical effects are involved: the vibration of the electron charge and spin moment due to vacuum fluctuations, and the radiation reaction of the charge. It is found that the positive sign of g-2 is entirely due to the radiation reaction which slows down the cyclotron motion, whereas the Lamb shift results from the averaging of the Coulomb potential by the vibrating electron (Weltons picture). Many-particle effects and the contributions of relativistic modes are briefly discussed. They do not seem to alter these conclusions.