Controlling the quantum state of light and matter with cavity QED

Experimental progress in atomic, molecular and optical physics, at the quantum level, as well as in condensed matter physics, has over the last few decades allowed us to not only observe quantum phenomena in nature, but also control them. This has led to the idea of “engineering” quantum systems, where microscopic constituents, such as single atoms, are manipulated in a precise manner to achieve some desired behaviour. By now, this has become a central theme in contemporary low-energy quantum physics. The change in viewpoint, from “observing” to “controlling,” leads to very different goals and opportunities, for experimentalists and theorists alike. This thesis contains seven publications on the following two related topics: i) engineering interactions in quantum systems, allowing for a large degree of control of system parameters, and ii) quantifying and understanding quantum correlations in dynamical quantum systems. The latter is an important goal in quantum information science, necessary to take advantage of quantum systems for information processing tasks, and thus expected to be central for future quantum technologies