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

TL;DR

This paper analyzes gravitational time dilation as a potential source of decoherence in interferometric experiments, comparing it with other known effects and identifying the conditions needed for gravitational decoherence to dominate.

Contribution

It provides a detailed quantitative comparison of gravitational decoherence with other environmental effects and discusses experimental requirements to observe gravitational decoherence.

Findings

Current experiments are several orders of magnitude away from observing gravitational decoherence.

Gravitational decoherence can dominate if experiments are scaled up and environmental effects are minimized.

Achieving the necessary conditions requires larger systems, cooling, and isolation.

Abstract

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.