An atom interferometer supplies atomic preparation, coherent splitting and recombination, and a readout of the output populations. In a light-pulse apparatus, a cooled atomic cloud interacts with controlled laser pulses during flight, and state-selective detection measures the populations after the final pulse.
For ideal equal interfering amplitudes, one output has probability , where is the relative wave phase and the interferometric visibility. Scanning a laser phase produces fringes. Vibrations, phase noise, unequal path populations and information distinguishing the paths can reduce their visibility; simply detecting two atomic groups does not establish wave interference.
New to topics? Read the docs here!