Atoms in External Fields

Sections 8.1–8.4 present the essentials on these topics. The reader should become well acquainted with these key tools in modern atomic physics – even though parts of it may seem somewhat strenuous at first sight. These concepts are essential also for molecular physics, as well as for a fundamental understanding of many properties of condensed matter and plasmas. This will be illustrated in Sects. 8.1.6, 8.1.7, 8.1.8, 8.2.10, 8.3 and 8.4.2 for a number of selected examples. In these presentations the reader will also find various references to modern developments in atomic physics which will brighten the study of these “classical” themes with currently hot topics – as e.g. “fast and slow” light in Sect. 8.4.4 or, in Sect. 8.5, with a first approach towards the rapidly developing modern research field of matter in intense and ultra-intense laser fields.