Comment on "Single Photon Experiments and Quantum Complementarity" by D. Georgiev

Christoph Braig, Patrick Zarda, Christian Kurtsiefer +1 more

Marian Kupczyński

Genovese and Piacentini [] claim that, in a recent experiment [S. Virzì , ], the Bell parameter was measured on a single pair of photons, thus challenging several conclusions and discussions on the meaning of Bell inequalities as well as certain quantum mechanical interpretations. We explain that the parameter measured in the experiment of Virzì is not the Bell parameter S , which has been discussed and estimated in many loophole-free tests. Therefore, this experiment neither challenges our understanding of Bell tests nor allows having doubts about Bohr complementarity and contextuality.

Gerhard Rempe, W. P. Schleich, Marlan O. Scully +1 more

R. W. Menzel, Dirk Puhlmann, Axel Heuer

Single photon first order interferences of spatially separated regions from the cone structure of spontaneous parametric down conversion allow for analyzing the role of the mode function in quantum optics. In earlier experiments the role of the vacuum fields could be demonstrated in induced coherence experiments as the source of complementarity \cite{Heu14}. Here the spatial coherence properties of these vacuum fields are measured and as the physical reason for complementarity in single photon quantum optics demonstrated.

Aurélien Drezet

R. W. Menzel, Dirk Puhlmann, Axel Heuer

In earlier experiments the role of the vacuum fields could be demonstrated as the source of complementarity with respect to the temporal properties (Heuer et al., Phys. Rev. Lett. 114:053601, 2015). Single photon first order interferences of spatially separated regions from the cone structure of spontaneous parametric down conversion allow for analyzing the role of the mode function in quantum optics regarding the complementarity principle. Here the spatial coherence properties of these vacuum fields are demonstrated as the physical reason for complementarity in these single photon quantum optical experiments. These results are directly connected to the mode picture in classical optics. The properties of the involved vacuum fields selected via the measurement process are the physical background of the complementarity principle in quantum optics.