Probing Short-Range Gravity using Quantum Reflection

We present theoretical calculations and an experimental design for an atom interferometer capable of measuring atom-surface interactions at short length scales. A low-density Bose condensate is launched toward the surface at a low velocity. A fraction of the atoms quantum-reflect from the long-range Casimir-Polder potential, at a distance of a few micrometers. The reflected atom wave produced a transient standing wave pattern in the atomic density, which can be imaged by standard techniques. The phase of this standing wave is sensitive to the atom-surface interaction potential. By comparing the reflections from surfaces with different mass density, it is possible to search for anomalous short-range gravitational effects with a sensitivity approaching that obtained using macroscopic test masses in the micrometer regime.