Optical elements for slowly moving neutral atoms based on magnetic fields

Magnetostatic and quasi-magnetostatic devices can act as optical elements for the de Broglie waves of magnetic atoms, i.e. atoms with a net static magnetic dipole moment in the ground (or isomeric) state. Such magnetic atom optical elements complement, and are alternatives to, resonantly tuned laser atom optical elements which rely on dynamically generated electric dipole moments. The physical principles behind such magnetic devices are discussed briefly, as well as the potential problems of decoherence and its management. The way that these optical elements may be realized is also discussed, with special reference to mirrors and static and quasi-static gratings. Gratings are important to atom interferometry as they can act as beam-splitters.