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arXiv · 2104.10703

On detecting violation of local realism with photon-number resolving weak-field homodyne measurements

Tamoghna Das·Marcin Karczewski·Antonio Mandarino·Marcin Markiewicz·Bianka Woloncewicz·Marek Żukowski
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Abstract

Non-existence of a local hidden variables (LHV) model for a phenomenon benchmarks its use in device-independent quantum protocols. Nowadays photon-number resolving weak-field homodyne measurements allow realization of emblematic gedanken experiments. Alas, claims that we can have no LHV models for such experiments on (a) excitation of a pair of spatial modes by a single photon, and (b) two spatial modes in a weakly squeezed vacuum state, involving constant local oscillator strengths, are unfounded. For (a) an exact LHV model resolves the dispute on the "non-locality of a single photon" in its original formulation. It is measurements with local oscillators on or off that do not have LHV models.

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Tamoghna Das, Marcin Karczewski, Antonio Mandarino, Marcin Markiewicz, Bianka Woloncewicz, Marek Żukowski. 2021-04-21. On detecting violation of local realism with photon-number resolving weak-field homodyne measurements. https://doi.org/10.1088/1367-2630/ac54c8

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