Quantum state control via tunneling in an optical potential

Summary form only given. The development of methods to manipulate and measure the quantum mechanical state of a physical system represents one of the great challenges of modern science. Examples of systems in which quantum control is sought or has been accomplished include trapped atomic ions, the electromagnetic field, Rydberg electrons, nuclear spins and vibrations in molecules, and chemical reactions. For many years a paradigm for quantum coherent evolution has been the occurrence of tunneling in macroscopic and mesoscopic double-well potentials. Much theoretical work has been done on this model system, but a series of fundamental questions remain to be addressed in well-controlled experiments, notably whether coherent evolution can be enforced in the presence of a noisy environment, by suitable perturbations of the state of the tunneling particle. The challenge is to find simple physical systems, which can be made to interact with a well characterized environment in a controlled manner.