Quantum Zeno effect in recent experiments with Bose-Einstein condensates

If frequent measurements are performed on a quantum system,in order to ascertain whether it is still in its initial state,transitions to other states are hindered and the quantum Zenoeffect takes place.

We look at some recent experiments with Bose-Einstein condensates and discuss their practical relevance and fiuture prospects. We focus on decoherence effects.

We also stress that the quantum Zeno effect does not necessarily freeze everything. On the contrary, for frequent projections onto a multi-dimensional subspace, the system can evolve away from its initial state, although it remains in the subspace defined by the measurement. This is named "quantum Zeno dynamics" and has interesting features.