"The Abbe–Rayleigh diffraction limit constrains spatial resolution for classical imaging methods. Quantum imaging exploits correlations between photons to reproduce structures with higher resolution. Quantum-correlated 𝑁-photon states were shown to potentially surpass the classical limit by a factor of 1/𝑁, corresponding to the Heisenberg limit, using a method known as optical centroid measurement (OCM). In this work, the theory of OCM is reformulated for its application in imaging. Using entangled photon pairs and a recently developed integrated time-resolving detector array, OCM is implemented in a proof-of-principle experiment that demonstrates the expected enhancement. Those results show the relevance of entanglement for imaging at the Heisenberg limit."
