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Quantum-enhanced interferometry with large heralded photon-number states



G Thekkadath, M.E. Mycroft, B.A. Bell, C.G. Wade, A. Eckstein, David Phillips, R.B Patel, A. Buraczewski, Adriana Lita, Thomas Gerrits, Sae Woo Nam, M. Stobinska, A.I. Lvovsky, Ian Walmsley


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 sqrt(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 novel 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 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.
Physical Review Letters


quantum enhanced sensing, photon number resolving detectors, quantum optics


Thekkadath, G. , Mycroft, M. , Bell, B. , Wade, C. , Eckstein, A. , Phillips, D. , Patel, R. , Buraczewski, A. , Lita, A. , Gerrits, T. , Nam, S. , Stobinska, M. , Lvovsky, A. and Walmsley, I. (2020), Quantum-enhanced interferometry with large heralded photon-number states, Physical Review Letters, [online], (Accessed November 30, 2021)
Created June 14, 2020, Updated October 12, 2021