Rydberg Atoms and Radiation

Abstract

Most atomic physics experiments involve, in one way or another, the coupling of atoms with electromagnetic radiation. The order of magnitude of the atom-field interaction parameters thus sets the scale of the phenomena in the atomic physics world. These orders of magnitude can quite generally be obtained by simple back of the envelope calculations combining a small number of basic (non-independent) parameters such as the electron charge q, the fine structure constant α, the Bohr radius a₀, the atomic electric field F_a = q/4πε₀ a ²₀ . For example, the order of magnitude of the resonant optical frequencies ω or wavelengths λ are:

$${\rm{\lambda }}/2{\rm{\pi }} = {\rm{c}}/{\rm{\omega }} \simeq {{\rm{a}}_{0{\rm{ }}}}{{\rm{\alpha }}^{ - 1}},$$

((1))

Whereas the radiative decay rate of an ordinary excited state coupled to lower states by electric dipole transitions is of order of:

$$\Gamma = {\alpha ^3}\omega = c{\alpha ^4}{\rm{ a}}_0^{ - 1}.$$

((2))