GENERATION OF EINSTEIN-PODOLSKY-ROSEN PAIRS OF ATOMS

Pairs of atoms have been prepared in an entangled state of the Einstei n-Podolsky-Rosen (EPR) type. They were produced by the exchange of a s ingle photon between the atoms in a high Q cavity. The atoms, entangle d in a superposition involving two different circular Rydberg states, were separated by a distance of the order of 1 cm. At variance with mo st previous EPR experiments, this one involves massive particles. It c an be generalized to three or more atoms and opens the way to new test s of nonlocality in mesoscopic quantum systems.