Abstract

The experimental demonstration of Bose–Einstein condensation (BEC) in magnetically trapped atomic gases^1-3 has focused interest on the prospects for constructing a source of coherent matter waves, or atom laser. Indeed, a prototype device of this type has been demonstrated,⁴ and the first-order coherence properties of BEC atom sources have been demonstrated by the observation of interference fringes in collisions of separately prepared BECs.⁵ There is some controversy over the use of the laser analogy to describe such systems,⁶ in part because the theory of coherence has not yet been as fully developed for matter-wave as for optical-wave sources. We believe that a first-principles model of matter-wave coherence is needed to provide a framework within which one can give quantitative interpretation to experiments such a those of Burt et al.⁷ and Ketterle and Miesner,⁸ which are concerned with third- and second-order coherence functions, respectively.

© 1998 Optical Society of America