Fundamentals and mechanisms of quantum localization in multidimensional correlated systems

Coupled motion in many degrees of freedom is known to often show in classical mechanics unexpectedly localized quasiperiodic motion that could not have been anticipated from the potential function. Similar phenomena is observed in quantum theory and this article discusses the fundamental physics of such localization. It is argued below that a Born–Oppenheimer type approximation leads to dynamic potentials that make the nonobvious localization obvious. Applications are mentioned for photoselective chemistry, absorption spectroscopy, and chemical mechanisms.