Test Gravitational Effects on Quantum Entanglement with Fiber Interferometry

Quantum mechanics and Einstein’s general relativity are two well-established pillars of modern physics. Despite their individual revolutionary successes, reconciling them has remained an unsolved challenge, and no experimental observation to date has simultaneously required the principles of both for its explanation. The GRAVITES project (Gravitational Interferometry with Entangled States in Optical Fibers) aims to investigate gravitational effects on quantum entanglement and quantum superposition using a laboratory-scale setup [1]. I will describe this ongoing experiment designed to study the gravitationally induced phase shift of photons prepared in path-entangled states within a fiber interferometer, where the two arms are separated by a 2-meter height difference. This 30 km fiber interferometer achieves a strain sensitivity on the order of 1E-16, allowing two-photon entangled states to probe the interplay between gravitational fields and quantum mechanics [2]. This experiment will be the first to measure the effect of gravitational potential on a path-entangled state of light, marking a significant step toward precision quantum measurements that address fundamental questions about our universe. It also paves the way for future space-based experiments to test the effects of gravity on quantum phenomena [3].

[1] M. Zych, F. Costa, I. Pikovski, and C. Brukner. Nat. Comm. 2 (2011).

[2] C. Hilweg et al. New Journal of Physics, 19.3 (2017).

[3] David. Bruschi, et al. New Journal of Physics, 16 (2014).