Title: The Instability of a Quantum Superposition of Time Dilations
Abstract: Using the relativistic concept of time dilation we show that a superposition of gravitational potentials can lead to nonunitary time evolution. For sufficiently weak gravitational potentials one can still define, for all intents and purposes, a global coordinate system. A probe particle in a superposition of weak gravitational fields will, however, experience dephasing due to the different time dilations. The corresponding instability timescale is accessible to experiments, and can be used as a degree of macroscopicity. Finally, we suggest an experiment with smoothly tunable amplification in a microwave interferometer that allows a quantitative study of the quantum to classical boundary.
Reference: Louk Rademaker, Tom van der Reep, Nick Van den Broeck, Bob van Waarde, Marc de Voogd, Tjerk Oosterkamp; arXiv:1410.2303.