Colloquium on June 29, 2009

Dieter Meschede
Universität Bonn

"Playing quantum marbles or can we make individual atoms interfere with each other?"

Quantum gases confined by an optical lattices have recently received much attention as simulators for quantum many-particle systems, and they are advertised as important tools for quantum information science. In an alternative "bottom-up" approach small interacting quantum systems can be created with neutral atoms which resembles a bit children playing with microscopic marbles. In this lecture I will present our recent experimental advances where we have taken atomic marbles to the full quantum regime, i.e. to the observation of atomic matter wave interferences at the single atom level. For instance, we have realized the quantum analogue of Brownian motion, the quantum walk, a concept of relevance in quantum information science. New methods to cool single atoms to the motional ground state also open the potential for the creation of degenerate quantum states at the level of few atoms only.