Decoherence due to gravitational time dilation: Analysis of competing decoherence effects

•Debye's heat capacity is used at low temperatures.•Collisional decoherence is taken into account.•Gravitational decoherence is quantified against other competing decoherence effects.

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 a system as possible, to increase gravitational decoherence, cool it and isolate well enough to reduce thermal and collisional decoherence, and resolve very small distances.