Effects of spacetime fluctuations on quantum systems

Spacetime can be understood as some kind of spacetime foam of fluctuating bubbles or loops which is expected to be an outcome of a theory of quantum gravity. This should lead to a fluctuating spacetime. In our approach we assume that spacetime fluctuations manifest as classical stochastic fluctuations of the metric. It will be shown how quantum dynamics is affected and we discuss the following effects: (i) an apparent violation of the weak equivalence principle, (ii) a modification of the spreading of wavepackets, and (iii) a loss of quantum coherence.