Remarks about Bell-nonclassicality of a single photon

Das, Tamoghna; Karczewski, Marcin; Mandarino, Antonio; Markiewicz, Marcin; Woloncewicz, Bianka; Żukowski, Marek

doi:10.1016/j.physleta.2022.128031

Cited by 16 publications

(15 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The above analysis strongly suggests that in order to obtain a Bell violation in the considered experimental setup one should locally vary the local oscillator strengths of the beamsplitters from setting to setting. This is fully concurrent with our analysis of the setup presented in [3,9] and in the forthcoming work [6].…”

Section: Discussionsupporting

confidence: 79%

See 1 more Smart Citation

Comment on `Single particle nonlocality with completely independent reference states'

Das,

Karczewski,

Mandarino

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

We comment on the purported violation of local realism, by a single photon induced correlations between homodyne detectors, which one can find in: New J. Phys. 10, 113024 (2008), [arXiv:0807.0109]. The claim is erroneous, due to a calculational mistake. As the result is the basis of other claims in the paper, they are unsubstantiated. I. INTRODUCTIONRef. [1] seems to be the first work to show that a single photon in a superposition of being in one or another exit of a 50-50 beamsplitter can induce correlations, in homodyne measurements at two spatially separated locations, which violate local realism. The work is an element of a long discussion concerning the suggested by Tan, Walls and Collett [2] "non-locality of a single photon". Ref. [1] discusses essentially the same setup as [2], Fig. 1. The difference is that in [2] the local settings of the homodyne measurements were defined by the phases of local oscillator fields, whereas in [1] the settings are defined by transmittivities of the beamsplitters at the final local measurement stations. In both configurations, of [2] and [1], the (moduli of) amplitudes of the local oscillators are fixed, they do not change between settings, and are the same for Alice and Bob. Ref.[2] also claimed a violation of local realism, however this was based on the authors' usage of Bell-like inequalities which involve an additional assumption, except the usual ones needed to derive Bell inequalities. Thus the claim of [2] is unfounded. A final proof of this is given in [3], where one can find an explicit local realistic model for the original Tan-Walls-Collett correlations.The attempt of Ref. [1] does not fall into this trap of incorrect Bell inequalities. They use the good old CHSH ones. Still the violation which they claim does not occur. There is an error in calculation. We show this below.

show abstract

Section: Discussionsupporting

confidence: 79%

“…In a forthcoming manuscript[6] we show that this is a robust feature: even for states with a vacuum component of norm of few percent, the Hardy method gives operationally inaccessible violations of a relevant Bell inequality. Simply, they are very small.…”

mentioning

confidence: 86%

Comment on `Single particle nonlocality with completely independent reference states'

Das,

Karczewski,

Mandarino

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…Our detailed analysis of the experiment in reference [23] shows, that the purported CHSH inequality violation never occurs for the measurement setup proposed by the authors. This would be explicitly discussed in a forthcoming comment [46]. For the case of different intensities of the local oscillator fields, namely when the moduli of the amplitudes α 1 = α 2 , the formula for the coincidence probabilities is obtainable via a similar calculation, and reads…”

Section: Ramifications Concerning the Claims On 'Non-locality Of A Si...mentioning

confidence: 99%

Wave–particle complementarity: detecting violation of local realism with photon-number resolving weak-field homodyne measurements

et al. 2022

Self Cite

View full text Add to dashboard Cite

Nowadays photon-number resolving weak-field homodyne measurements allow realization of emblematic gedankenexperiments revealing correlations of optical fields. This covers 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. Proving Bell nonclassicality of such correlations demands measurements of complementary observables. We show that typical arrangement of weak-field homodyne detection with measurement settings defined by phases of local oscillators of constant strength does not provide enough complementarity for confirming Bell nonclassicality. In the case of experiment (a) we provide an exact local hidden variable model restoring all quantum probabilities, whereas in the case of experiment (b) we show that the claims of its nonclassicality are unfounded. A full complementarity of wave aspects vs particle (number) can be achieved in a measurement situation in which respectively the local oscillators are on or off. This is shown to lead to an operational scenario, in the case of both experiments (a) and (b), which reveals indisputable violations of local realism. Such schemes may find possible applications in device-independent quantum protocols.

show abstract

“…Thus the claim of [2] is unfounded. A final proof of this is given in [3], where one can find an explicit local realistic model for the original Tan-Walls-Collett correlations.…”

Section: Introductionmentioning

confidence: 86%

Comment on ‘Single particle nonlocality with completely independent reference states’

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

Remarks about Bell-nonclassicality of a single photon

Cited by 16 publications

References 25 publications

Comment on `Single particle nonlocality with completely independent reference states'

Comment on `Single particle nonlocality with completely independent reference states'

Wave–particle complementarity: detecting violation of local realism with photon-number resolving weak-field homodyne measurements

Comment on ‘Single particle nonlocality with completely independent reference states’

Contact Info

Product

Resources

About