Theory and applications of atomic and ionic polarizabilities

Abstract

Atomic polarization phenomena impinge upon a number of areas and processes in\nphysics. The dielectric constant and refractive index of any gas are examples\nof macroscopic properties that are largely determined by the dipole\npolarizability. When it comes to microscopic phenomena, the existence of\nalkaline-earth anions and the recently discovered ability of positrons to bind\nto many atoms are predominantly due to the polarization interaction. An\nimperfect knowledge of atomic polarizabilities is presently looming as the\nlargest source of uncertainty in the new generation of optical frequency\nstandards. Accurate polarizabilities for the group I and II atoms and ions of\nthe periodic table have recently become available by a variety of techniques.\nThese include refined many-body perturbation theory and coupled-cluster\ncalculations sometimes combined with precise experimental data for selected\ntransitions, microwave spectroscopy of Rydberg atoms and ions, refractive index\nmeasurements in microwave cavities, ab initio calculations of atomic structures\nusing explicitly correlated wave functions, interferometry with atom beams, and\nvelocity changes of laser cooled atoms induced by an electric field. This\nreview examines existing theoretical methods of determining atomic and ionic\npolarizabilities, and discusses their relevance to various applications with\nparticular emphasis on cold-atom physics and the metrology of atomic frequency\nstandards.\n