Robustness of noise-present Bell's inequality violation by entangled state

TL;DR

This paper investigates how robust Bell's inequality violations are in entangled states when both colored and white noise are present, using a two-parameter density matrix model and comparing with experimental data.

Contribution

It introduces a two-parameter density matrix model to analyze Bell's inequality violation robustness under mixed noise conditions, extending previous one-parameter models.

Findings

Bell's inequality violation remains robust under certain noise fractions.

Comparison shows good agreement with experimental data.

The model generalizes previous approaches by including both white and colored noise.

Abstract

The robustness of Bell's inequality (in CHSH form) violation by entangled state in the simultaneous presence of colored and white noise in the system is considered. A twophoton polarization state is modeled by twoparameter density matrix. Setting parameter values one can vary the relative fraction of pure entangled Bell's state as well as white and colored noise fractions. Bell's operator-parameter dependence analysis is made. Computational results are compared with experimental data [quant-ph/0511265] and with results computed using a oneparameter density matrix [doi: 10.1103/PhysRevA.72.052112], which one can get as a special case of the model considered in this work.