Quantum phenomena such as entanglement can improve fundamental limits on the sensitivity of a measurement probe. In optical interferometry, a probe consisting of N entangled photons provides up to a N enhancement in phase sensitivity compared to a classical probe of the same energy. Here, we employ high-gain parametric down-conversion sources and photon-number-resolving detectors to perform interferometry with heralded quantum probes of sizes up to N=8 (i.e. measuring up to 16-photon coincidences). Our probes are created by injecting heralded photon-number states into an interferometer, and in principle provide quantum-enhanced phase sensitivity even in the presence of significant optical loss. Our work paves the way towards quantum-enhanced interferometry using large entangled photonic states.
@article{arxiv.2006.08449,
title = {Quantum-enhanced interferometry with large heralded photon-number states},
author = {G. S. Thekkadath and M. E. Mycroft and B. A. Bell and C. G. Wade and A. Eckstein and D. S. Phillips and R. B. Patel and A. Buraczewski and A. E. Lita and T. Gerrits and S. W. Nam and M. Stobińska and A. I. Lvovsky and I. A. Walmsley},
journal= {arXiv preprint arXiv:2006.08449},
year = {2020}
}
Comments
15 pages, 9 figures; includes Supplemental Material