Harnessing optical disorder for Bell inequalities violation

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Courme, Baptiste, Joly, Malo, Makowski, Adrian, Gigan, Sylvain, Defienne, Hugo
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866915513552076800
author Courme, Baptiste
Joly, Malo
Makowski, Adrian
Gigan, Sylvain
Defienne, Hugo
author_facet Courme, Baptiste
Joly, Malo
Makowski, Adrian
Gigan, Sylvain
Defienne, Hugo
contents Bell inequalities are a cornerstone of quantum physics. By carefully selecting measurement bases (typically polarization), their violation certifies quantum entanglement. Such measurements are disrupted by the presence of optical disorder in propagation paths, including polarization or spatial mode mixing in fibers and through free-space turbulence. Here, we demonstrate that disorder can instead be exploited as a resource to certify entanglement via a Bell inequality test. In our experiment, one photon of a polarization-entangled pair propagates through a commercial multimode fiber that scrambles spatial and polarization modes, producing a speckle pattern, while the other photon remains with the sender. By spatially resolving the speckle intensity pattern, we naturally access a large set of random and unknown polarization projections. We show that this set is statistically sufficient to violate a Bell inequality, thereby certifying entanglement without requiring active correction techniques. Our approach provides a fundamentally new way to test Bell inequalities, eliminating the need for an explicit choice of measurement basis, and offering a practical solution for entanglement certification in real-world quantum communication channels where disorder is unavoidable.
format Preprint
id arxiv_https___arxiv_org_abs_2509_21052
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Harnessing optical disorder for Bell inequalities violation
Courme, Baptiste
Joly, Malo
Makowski, Adrian
Gigan, Sylvain
Defienne, Hugo
Quantum Physics
Bell inequalities are a cornerstone of quantum physics. By carefully selecting measurement bases (typically polarization), their violation certifies quantum entanglement. Such measurements are disrupted by the presence of optical disorder in propagation paths, including polarization or spatial mode mixing in fibers and through free-space turbulence. Here, we demonstrate that disorder can instead be exploited as a resource to certify entanglement via a Bell inequality test. In our experiment, one photon of a polarization-entangled pair propagates through a commercial multimode fiber that scrambles spatial and polarization modes, producing a speckle pattern, while the other photon remains with the sender. By spatially resolving the speckle intensity pattern, we naturally access a large set of random and unknown polarization projections. We show that this set is statistically sufficient to violate a Bell inequality, thereby certifying entanglement without requiring active correction techniques. Our approach provides a fundamentally new way to test Bell inequalities, eliminating the need for an explicit choice of measurement basis, and offering a practical solution for entanglement certification in real-world quantum communication channels where disorder is unavoidable.
title Harnessing optical disorder for Bell inequalities violation
topic Quantum Physics
url https://arxiv.org/abs/2509.21052