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Gravitationally induced entanglement in atom interferometry

Richard Howl1,*, Nathan Cooper2, and Lucia Hackermüller2

  • *Contact author: richard.howl@rhul.ac.at
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Phys. Rev. A 114, 023306 – Published 5 August, 2026

DOI: https://doi.org/10.1103/l62d-gz5c

Abstract

A promising route to testing quantum gravity in the laboratory is to look for gravitationally induced entanglement (GIE) between two or more quantum matter systems. To date, proposed tests have primarily focused on microsolid platforms prepared in highly nonclassical states, such as N00N states or strongly squeezed states. Here, we instead consider measuring GIE in atom interferometry as evidence of quantum gravity. We propose placing two atom interferometers next to each other in parallel and looking for correlations in the atom-number statistics at their output ports. Importantly, GIE is possible without challenging macroscopic superposition states, such as N00N or Schrödinger-cat states. Instead, GIE can arise using coherent, near-classical atomic states, substantially reducing the experimental complexity. Observing the effect in this regime would require the total mass of the atom interferometers to be near the Planck mass scale. However, we show that state-of-the-art quantum squeezing techniques in cold-atom systems can significantly lower this mass requirement, and outline realistic pathways by which the necessary mass scales could be achieved in the near future, placing laboratory tests of GIE with atom interferometers within reach.

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Phys. Rev. A 114, 023306– Published 5 August, 2026
  • Received 12 September 2025
  • Revised 29 June 2026
  • Accepted 1 July 2026
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