Recently, a static gravitational field, such as that of the Earth, was
proposed as a new source of decoherence [1]. We study the conditions under
which it becomes the dominant decoherence effect in typical interferometric
experiments. The following competing sources are considered: spontaneous
emission of light, absorption, scattering with the thermal photons and
collisions with the residual gas. We quantify all these effects. As we will
see, current experiments are off by several orders of magnitude. New ideas are
needed in order to achieve the necessary requirements: having as large as
system as possible, to increase gravitational decoherence, cool it and isolated
well enough to reduce thermal and collisional decoherence, and resolve very
small distances.Comment: 6 pages, 3 figure
