Emulation of gravitational waves in curved spacetimes with entangled photon states

Ivan Fernández-Corbatón,^1,2 Mauro Cirio,^1,2 Alexander Büse,^1,2 Lucas Lamata,³ Enrique Solano,^3,4 and Gabriel Molina-Terriza^1,2

¹Department of Physics & Astronomy, Macquarie University, Australia

²ARC Center for Engineered Quantum Systems, Macquarie University, North Ryde, New South Wales 2109, Australia

³Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, E-48080 Bilbao, Spain

⁴IKERBASQUE, Basque Foundation for Science, Alameda Urquijo 36, 48011 Bilbao, Spain

Gravitational waves, as predicted by Einstein’s general relativity theory, appear as ripples in the fabric of spacetime traveling at the speed of light. We have formally proved that the propagation of small amplitude gravitational waves in a curved spacetime is equivalent to the propagation of a subspace of electromagnetic tensor waves. This subspace can be realized using entangled photon states. We use the result to propose a path to emulate the propagation of gravitational waves in curved spacetimes by means of experimental electromagnetic setups featuring metamaterials.