Quantum entanglement measures Earth’s rotation

by Giampaolo Pitruzzello

Interferometry is one of the most sensitive techniques available to test physical theories and make measurements. In particular, optical ring interferometers based on the Sagnac effect are commonly used to measure rotation, but their performance is constrained by the shot-noise limit. Employing quantum states of light allows for more sensitive optical phase measurements as compared to classical-light scenarios.

Now, writing in Science Advances, Raffaele Silvestri and colleagues from the University of Vienna report a quantum-based optical-fibre interferometer sufficiently sensitive to measure the rotation of the Earth (R. Silvestri et al. Sci. Adv. https://doi.org/10.1126/sciadv.ado0215; 2024).

Check out the full article here.