Twin beam quantum-enhanced correlated interferometry for testing fundamental physics

• Published in: Communications physics Vol. 3; no. 1
• Main Authors: Pradyumna, S. T., Losero, E., Ruo-Berchera, I., Traina, P., Zucco, M., Jacobsen, C. S., Andersen, U. L., Degiovanni, I. P., Genovese, M., Gehring, T.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 02.06.2020; Nature Publishing Group
• Subjects: 639/624/400/482; 639/766/400; 639/766/483/1255; Correlation; Frequencies; Interferometers; Interferometry; Physics; Physics and Astronomy; Shot noise
• ISSN: 2399-3650; 2399-3650
• DOI: 10.1038/s42005-020-0368-5

Quantum metrology deals with improving the resolution of instruments that are otherwise limited by shot noise and it is therefore a promising avenue for enabling scientific breakthroughs. The advantage can be even more striking when quantum enhancement is combined with correlation techniques among several devices. Here, we present and realize a correlation interferometry scheme exploiting bipartite quantum correlated states injected in two independent interferometers. The scheme outperforms classical analogues in detecting a faint signal that may be correlated/uncorrelated between the two devices. We also compare its sensitivity with that obtained for a pair of two independent squeezed modes, each addressed to one interferometer, for detecting a correlated stochastic signal in the MHz frequency band. Being the simpler solution, it may eventually find application to fundamental physics tests, e.g., searching for the effects predicted by some Planck scale theories. Quantum light injected in one interferometer has demonstrated to improve the phase sensitivity in relevant applications. Here, the authors analyse and demonstrate the potential advantage of quantum light, in particular quantum correlated bipartite states, in a system of two interferometers aimed at the detection of Planck scale effects.