# Quantum nonlocality for entanglement of quasiclassical states

## TL;DR

This paper introduces a new Bell correlation operator framework that enables nearly maximal violation of Bell inequalities with entangled quasiclassical states, revealing stronger nonlocality for quantum technologies.

## Contribution

A novel Bell correlation operator framework allowing near-maximal violation with high entanglement, surpassing previous limitations for large systems.

## Key findings

- Achieves nearly maximal Bell violation with high entanglement.
- Reveals stronger nonlocality than previous methods.
- Provides a scheme for implementing measurement gates for quantum information.

## Abstract

Entanglement of quasiclassical (coherent) states of two harmonic oscillators leads to striking quantum effects and is useful for quantum technologies. These effects and applications are closely related to nonlocal correlations inherent in these states, manifested by the violation of Bell inequalities. With previous frameworks, this violation is limited by the size of the system, which does not approach the maximum even when the amount of entanglement approaches its maximum. Here we propose a new version of Bell correlation operators, with which a nearly maximal violation can be obtained as long as the associated entanglement approximates to the maximum. Consequently, the revealed nonlocality is significantly stronger than those with previous frameworks for a wide range of the system size. We present a new scheme for realizing the gate necessary for measurement of the nonlocal correlations. In addition to the use in test of quantum nonlocality, this gate is useful for quantum information processing with coherent states