The authors describe an experimental scheme capable of simultaneously demonstrating signatures of quantum theory and general relativity by using entangled multi-photon states to measure space-time curvature. Contrary to analogous experiments with massive test particles, the photonic setup eludes a purely Newtonian description of the gravitational phase shift. Moreover, multi-photon states allow for curvature measurements at altitudes smaller than those required for classical or single-photon measurements.
T. Mieling, C. Hilweg, P. Walther
Measuring space-time curvature using maximally path-entangled quantum states
Physical Review A 106, L031701 (2022).
