Dominique Spehner (Univ. Grenoble)

Decoherence and quantum measurements.


Decoherence is an irreversible dynamical process transforming certain linear superpositions of wavepackets of a quantum system into a ``statistical mixture '' of these wavepackets. It can be explained by invoking the coupling of the system with its environment as well as a loss of information about the state of this environment. We will focus on the important following question: how long does this disappearance of quantum superpositions takes? Various models will be investigated heuristically, including a tripartite system-pointer-bath model illustrating a quantum measurement.