TIME SELECTION IN ATOMIC STERN-GERLACH INTERFEROMETRY

As shown recently by Zawisky, Rauch, and Hasegawa in neutron interfero metry [Phys. Rev. A 50, 5000 (1994)], the interference pattern obtaine d with a low-intensity particle beam is deeply modified when a selecti on is made of the time intervals between successive detected events. E xperiments of the same type performed with a Stern-Gerlach interferome ter using a metastable hydrogen atom beam are described. Results very similar to those of the neutron experiment are obtained, in particular a strong enhancement of the contrast when large time intervals are se lected.