Atoms in dark atomic ground states do not interact with the laser light present and are therefore not susceptible to spontaneous processes. Laser cooling populates these states. Confinement of atoms in dark states in a (periodic) gauge potential allows for a lattice of atoms with a very low decay rate, a dark lattice. A dark lattice is a promising system to observe Bloch oscillations of neutral atoms, i.e., periodic excursion across the Brillouin zone in a uniform force field.

• Received 6 July 1995

DOI:https://doi.org/10.1103/PhysRevLett.76.1788