Bell's theorem is typically understood as the proof that quantum theory is incompatible with local hidden-variable models. More generally, we can see the violation of a Bell inequality as witnessing the impossibility of explaining quantum correlations with classical causal models. The violation of a Bell inequality, however, does not exclude classical models where some level of measurement dependence is allowed, that is, the choice made by observers can be correlated with the source generating the systems to be measured. Here, we show that the level of measurement dependence can be quantitatively upper bounded if we arrange the Bell test within a network. Furthermore, we also prove that these results can be adapted in order to derive nonlinear Bell inequalities for a large class of causal networks and to identify quantumly realizable correlations that violate them.

Causal Networks and Freedom of Choice in Bell's Theorem / Chaves, R; Moreno, G; Polino, E; Poderini, D; Agresti, I; Suprano, A; Barros, Mr; Carvacho, G; Wolfe, E; Canabarro, A; Spekkens, Rw; Sciarrino, F. - In: PRX QUANTUM. - ISSN 2691-3399. - 2:4(2021). [10.1103/PRXQuantum.2.040323]

Causal Networks and Freedom of Choice in Bell's Theorem

Polino, E;Poderini, D;Agresti, I;Suprano, A;Carvacho, G;Sciarrino, F
Ultimo
2021

Abstract

Bell's theorem is typically understood as the proof that quantum theory is incompatible with local hidden-variable models. More generally, we can see the violation of a Bell inequality as witnessing the impossibility of explaining quantum correlations with classical causal models. The violation of a Bell inequality, however, does not exclude classical models where some level of measurement dependence is allowed, that is, the choice made by observers can be correlated with the source generating the systems to be measured. Here, we show that the level of measurement dependence can be quantitatively upper bounded if we arrange the Bell test within a network. Furthermore, we also prove that these results can be adapted in order to derive nonlinear Bell inequalities for a large class of causal networks and to identify quantumly realizable correlations that violate them.
2021
Bell inequalities; local-hidden-variable model; measurement dependence; quantum networks
01 Pubblicazione su rivista::01a Articolo in rivista
Causal Networks and Freedom of Choice in Bell's Theorem / Chaves, R; Moreno, G; Polino, E; Poderini, D; Agresti, I; Suprano, A; Barros, Mr; Carvacho, G; Wolfe, E; Canabarro, A; Spekkens, Rw; Sciarrino, F. - In: PRX QUANTUM. - ISSN 2691-3399. - 2:4(2021). [10.1103/PRXQuantum.2.040323]
File allegati a questo prodotto
File Dimensione Formato  
Chaves_Causal Networks_2021.pdf

accesso aperto

Tipologia: Versione editoriale (versione pubblicata con il layout dell'editore)
Licenza: Creative commons
Dimensione 2 MB
Formato Adobe PDF
2 MB Adobe PDF

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1619982
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 23
  • ???jsp.display-item.citation.isi??? 20
social impact