We show that a recent claim that matter wave interferometers have a much
higher sensitivity than laser interferometers for a comparable physical setup
is unfounded. We point out where the mistake in the earlier analysis is made.
We also disprove the claim that only a description based on the geodesic
deviation equation can produce the correct physical result. The equations for
the quantum dynamics of non-relativistic massive particles in a linearly
perturbed spacetime derived here are useful for treating a wider class of
related physical problems. A general discussion on the use of atom
interferometers for the detection of gravitational waves is also provided.Comment: 16 pages, REVTeX4; minor changes, one figure and a few references
were added, an additional appendix was included where we explain why,
contrary to the claims in gr-qc/0409099, the effects due to the reflection
off the mirrors cancel out in the final result for the phase shif