DELAYED CHOICES IN ATOM STERN-GERLACH INTERFEROMETRY

Delayed-choice experiments have been performed using an atomic Stern-G erlach interferometer operating with a low-intensity beam of metastabl e hydrogen atoms. By use of a fast-commutable analyzer, it is possible to modify the operating mode of the interferometer while the atom has already entered the device. Various types of delayed-choice experimen ts have been carried out to check the standard interpretation of quant um-mechanics. Within the experimental accuracy, our results do not sho w any discrepancy between permanent and delayed-choice operating modes of the interferometer.