# Many-body Bell inequalities for bosonic qubits

### Submission summary

 As Contributors: Jan Chwedeńczuk Arxiv Link: https://arxiv.org/abs/2109.15156v3 (pdf) Date accepted: 2022-04-14 Date submitted: 2022-04-04 11:32 Submitted by: Chwedeńczuk, Jan Submitted to: SciPost Physics Core Academic field: Physics Specialties: Atomic, Molecular and Optical Physics - Theory Quantum Physics Approach: Theoretical

### Abstract

Since John Bell formulated his paramount inequality for a pair of spin-$1/2$ particles, quantum mechanics has been confronted with the postulates of local realism with various equivalent configurations. Current technology, with its advanced manipulation and detection methods, allows to extend the Bell tests to more complex structures. The aim of this work is to analyze a set of Bell inequalities suitable for a possibly broad family of many-body systems with the focus on bosonic qubits. We develop a method that allows for a step-by-step study of the many-body Bell correlations, for instance among atoms forming a two-mode Bose-Einstein condensate or between photons obtained from the parametric-down conversion. The presented approach is valid both for cases of fixed and non-fixed number of particles, hence it allows for a thorough analysis of quantum correlations in a variety of many-body systems.

Published as SciPost Phys. Core 5, 025 (2022)

Dear Prof. Toth,

Thank you again for your time devoted to handling of my manuscript. I would also like to thank the Referees for their positive comments and their final recommendations.

I fully agree with the revisions suggested by the Referees in this second round. In this resubmission, please find the manuscript with all their remarks taken into account.

I hope that after these modifications, the manuscript could be accepted for the SciPost Physics Core.

With kind regards,
Jan Chwedenczuk

### List of changes

1) In this revised manuscript, the minor corrections have been applied throughout the text.
2) Also, the text has been modified so that it refers to many-body Bell correlations rather than many-body nonlocality.