Unified time, frequency picture of ultrafast atomic excitation in strong fields

New insight that light sometimes needs to be treated as an electromagnetic wave and sometimes as a stream of energy quanta called photons is as old as quantum physics. In the case of interaction of strong laser fields with atoms the dualism finds its analogue in the intuitive pictures used to explain ionization and excitation: The multiphoton picture and the tunneling picture. In a combined experimental and theoretical study on ultrafast excitation of atoms in intense short pulse laser fields, scientists succeeded to show that the prevailing and seemingly disparate intuitive pictures usually used to describe interaction of atoms with intense laser fields can be ascribed to a single nonlinear process.

(via WSJ)