Atom interferometry

Abstract The possibility of interferometry with atoms follows directly from wave particle duality. The wave-like propagation of particles, such as atoms, means that they undergo interference and diffraction in an analogous way to light. This chapter explains how such matter waves have been used in interferometers that measure rotation and gravitational acceler ation to a precision comparable with the best optical instruments. As in many important developments in physics, atom interferometry relies on simple principles-the first part of this chapter uses only elementary optics and the de Broglie relation.