Measuring space-time curvature using maximally path-entangled quantum states

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Experiments at the interface of quantum field theory and general relativity would greatly benefit theoretical research towards their unification. The gravitational aspects of quantum experiments performed so far can be explained either within Newtonian gravity or by Einstein's equivalence principle. Here, we describe a way to measure components of the Riemann curvature tensor with maximally path-entangled quantum states of light. We show that the entanglement-induced increase in sensitivity also holds for gravitationally induced phases in Mach-Zehnder interferometers. As a result, the height difference between the two interferometer arms necessary to rule out flat space-time by measuring gravity gradients can be significantly reduced.
Original languageEnglish
Article numberL031701
Number of pages5
JournalPhysical Review A
Issue number3
Publication statusPublished - 26 Sep 2022

Austrian Fields of Science 2012

  • 103024 Quantum field theory
  • 103026 Quantum optics
  • 103028 Theory of relativity


  • General Relativity
  • Quantum optics
  • Quantum entanglement

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