Detecting Many-Body Bell Nonlocality by Solving Ising Models

Irénée Frérot and Tommaso Roscilde
Phys. Rev. Lett. 126, 140504 – Published 9 April 2021
PDFHTMLExport Citation

Abstract

Bell nonlocality represents the ultimate consequence of quantum entanglement, fundamentally undermining the classical tenet that spatially separated degrees of freedom possess objective attributes independently of the act of their measurement. Despite its importance, probing Bell nonlocality in many-body systems is considered to be a formidable challenge, with a computational cost scaling exponentially with system size. Here we propose and validate an efficient variational scheme, based on the solution of inverse classical Ising problems, which in polynomial time can probe whether an arbitrary set of quantum data is compatible with a local theory; and, if not, it delivers the many-body Bell inequality most strongly violated by the quantum data. We use our approach to unveil new many-body Bell inequalities, violated by suitable measurements on paradigmatic quantum states (the low-energy states of Heisenberg antiferromagnets), paving the way to systematic Bell tests in the many-body realm.

  • Figure
  • Figure
  • Received 21 May 2020
  • Revised 29 November 2020
  • Accepted 5 March 2021

DOI:https://doi.org/10.1103/PhysRevLett.126.140504

© 2021 American Physical Society

Physics Subject Headings (PhySH)

Quantum Information, Science & TechnologyGeneral Physics

Authors & Affiliations

Irénée Frérot1,2 and Tommaso Roscilde3

  • 1ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Avenida Carl Friedrich Gauss 3, 08860 Barcelona, Spain
  • 2Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany
  • 3Univ Lyon, Ens de Lyon, Univ Claude Bernard, CNRS, Laboratoire de Physique, F-69342 Lyon, France

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 126, Iss. 14 — 9 April 2021

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×