Decoherence denotes the environment-induced, dynamical destruction of quantum
coherence. It leads to a dynamical selection of a distinguished set of pure
states of the open system and counteracts the superposition principle in the
Hilbert space of the open system.
We will start with a general discussion of the dynamical structure which
leads to ideal environment-induced decoherence, that is to the destruction
of quantum coherence without damping. Basic concepts, such as dynamical
selection of a preferred basis, decoherence time, and the emergence of
coherent subspaces will be illustrated with the help of an analytically
solvable example. |