  We propose an experiment based on a Bose-Einstein condensate interferometer
for strongly constraining fifth-force models. Additional scalar fields from
modified gravity or higher dimensional theories may account for dark energy and
the accelerating expansion of the Universe. These theories have led to proposed
screening mechanisms to fit within the tight experimental bounds on fifth-force
searches. We show that our proposed experiment would greatly improve the
existing constraints on these screening models by many orders of magnitude.
