Testing superpositions of detector trajectories
Phys. Rev. D 114, 076009 – Published 5 October, 2026
DOI: https://doi.org/10.1103/xw83-hyh5
Abstract
We propose a realizable experiment to test the response of a particle detector prepared in a superposition of locations interacting with a relativistic quantum field. Using a beam splitter to prepare two superposed branches of a modulated laser probe, these branches are directed to intersect a pancake-shaped Bose-Einstein condensate at two separate locations. The branches are then recombined with another beam splitter. Heterodyning one of the outputs, the response function corresponding to an Unruh-DeWitt detector in a superposition of locations interacting with a ()-dimensional massless scalar field is shown to appear in the difference-photocurrent power spectrum. Operating beyond the standard quantum limit using squeezed light, the signal-to-noise ratio is estimated as for extracting the response function over a broad set of baseband frequencies.
