Effect of high frequency irradiation on the dynamical properties of weakly bound electrons

Abstract

We study how the behaviour of an electron in d.c. electric or magnetic fields changes when this electron is simultaneously interacting with a high frequency electromagnetic wave. The new dynamical properties of the electron are described by an effective hamiltonian that we derive using a quantum description of the electromagnetic field and including relativistic corrections up to order 1/c2. Besides a well-known mass-shift correction, one finds that the new dynamical properties of the electron can be described in terms of electric and magnetic form factors which have a simple physical interpretation. Finally, these general results are applied to 2 simple cases : perturbation of atomic Rydberg states and modification of the cyclotron and spin precession frequencies of an electron in a static homogeneous magnetic field.