Entanglement quantification via nonlocality

Yuwei Zhu, Xingjian Zhang, Xiongfeng Ma

Published 2023-03-15Version 1

Nonlocality, manifested by the violation of Bell inequalities, indicates quantum entanglement in the underlying system. A natural question that arises is how much entanglement is required for a given nonlocal behavior. In this paper, we explore this question by quantifying entanglement using a family of generalized Clauser-Horne-Shimony-Holt-type Bell inequalities. We focus on two entanglement measures, entanglement of formation and one-way distillable entanglement, which are related to entanglement dilution and distillation, respectively. We also study the interplay among nonlocality, entanglement, and measurement incompatibility. The result reveals that the relationship between entanglement and measurement incompatibility is not simply a trade-off under a fixed nonlocal behavior. In addition, we consider two realistic scenarios non-maximally entangled states and Werner states and apply our entanglement quantification results. By optimizing the Bell inequality for entanglement estimation, we derive analytical results for the entanglement of formation.