北京雁栖湖应用数学研究院

代昊

朱雨薇

2024年09月26日 10:30 至 11:30

A3-4-101

Zoom 637 734 0280 (BIMSA)

Nonlocality, manifested by the violation of Bell inequalities, indicates entanglement within a joint quantum system. A natural question is how much entanglement is required for a given nonlocal behavior. Here, we explore this question by quantifying entanglement using a family of generalized Clauser–Horne–Shimony–Holt-type Bell inequalities. Given a Bell-inequality violation, we derive analytical lower bounds on the entanglement of formation, a measure related to entanglement dilution. The bounds also lead to an analytical estimation of the negativity of entanglement. In addition, we consider one-way distillable entanglement tied to entanglement distillation and derive tight numerical estimates. With the additional assumptions of qubit-qubit systems, we find that the relationship between entanglement and measurement incompatibility is not simply a trade-off under a fixed nonlocal behavior. Furthermore, we apply our results to two realistic scenarios—non-maximally entangled and Werner states. We show that one can utilize the nonlocal statistics by optimizing the Bell inequality for better entanglement estimation.

Yuwei Zhu is a PhD candidate at Tsinghua University, where she is mentored by Professor Xiongfeng Ma. Her research focuses on the foundations of quantum theory, with particular interests in quantum nonlocality and (semi) self-testing in device-independent quantum information processing.