Entanglement measure and quantum violation of Bell-type inequality for a family of four-qubit entangled states

TL;DR

This paper investigates the relationship between entanglement measures and Bell inequality violations in four-qubit states, demonstrating complete violation and a non-monotonic relationship between entanglement and quantum violation.

Contribution

It introduces a detailed analysis of entanglement and Bell inequality violation for a specific family of four-qubit states, revealing their interdependence.

Findings

Bell-type inequality is fully violated by these states

Entanglement measure first decreases then increases with quantum violation

Entanglement and violation are non-monotonically related

Abstract

By calculating entanglement measures and quantum violation of Bell-type inequality, we reveal the relationship between entanglement measure and the amount of quantum violation for a family of four-qubit entangled states. It has been demonstrated that the Bell-type inequality is completely violated by these four-qubit entangled states. The plot of entanglement measure as a function of the expectation value of Bell operator shows that entanglement measure first decreases and then increases smoothly with increasing quantum violation.