Quantum position measurement of a shadow: beating the classical limit
Ermes Toninelli, M. Edgar, Paul‐Antoine Moreau, Graham M. Gibson, Giles D. Hammond, Miles J. Padgett · 2017
The precision with which the position of a shadow can be measured is classically limited by shot-noise. We achieve sub-shot-noise position sensitivity by jointly detecting correlated photons with a simple split-detector scheme.