Soft Matter and Complex Systems Seminar

The equation of quantum mechanics (Schrodinger and Dirac) are formally deterministic, that seems to forbid to introduce a fundamental uncertainty in the predictions one can make from given initial data, a difficulty in the logic present from the very beginnings of quantum mechanics. I shall explain how to deal with this question by returning to the original paper by Dirac on the emission of photons by an atom in an excited state. This is illustrated by a detailed discussion of the dynamics of a two-level atomic state pumped by a resonant classical field, something representing experimental situations.