近日，印度哈里什-钱德拉研究所的Aditi Sen(De)及其研究团队取得一项新进展。经过不懈努力，他们对高维非局域性对双噪声和顺序测量的鲁棒性进行研究。相关研究成果已于2024年6月28日在国际知名学术期刊《物理评论A》上发表。
该研究团队从测量噪声和状态噪声的双重角度研究了Collins-Linden-Gisin-Masser-Popescu (CGLMP)不等式违反的鲁棒性。为了量化这一现象，研究人员引入了一个名为“非局域区域面积”的度量，这一度量展现出了显著的维度优势。具体而言，随着维度的增加，与最大纠缠态相比，最大违反态在非局域区域面积上呈现出更为显著的增强效果，并且这种情况下增量的缩放速度比可见性的增长更为迅速。
此外，研究人员使用弱测量检验了CGLMP不等式顺序违反的鲁棒性，并发现即使在高维情况下，两个观察者的CGLMP不等式同时违反的情况仍然存在。研究人员注意到，信息增益和测量扰动之间的互补性表现为第一阶段可见性的降低和第二阶段可见性的增加。此外，可以添加到最大纠缠状态的白噪声量随着维数的增加而减少，从而使其具有两阶段违反，而对于最大违反状态则没有明显的变化。
附：英文原文
Title: Robustness of higher-dimensional nonlocality against dual noise and sequential measurements
Author: Saptarshi Roy, Asmita Kumari, Shiladitya Mal, Aditi Sen(De)
Issue&Volume: 2024/06/28
Abstract: The robustness of the violation of the Collins-Linden-Gisin-Masser-Popescu (CGLMP) inequality is investigated from the dual perspectives of noise in measurements and in states. To quantify it, we introduce a quantity called the area of the nonlocal region which reveals a dimensional advantage. Specifically, we report that with an increase in dimension, the maximally violating states show greater enhancement in the area of the nonlocal region in comparison to the maximally entangled states and the scaling of the increment in this case grows faster than visibility. Moreover, we examine the robustness of the sequential violation of the CGLMP inequality using weak measurements and find that even for higher dimensions, the simultaneous violation of the CGLMP inequalities of two observers as obtained for two-qubit states persists. We notice that the complementarity between information gain and disturbance from measurements is manifested by the decrease in the visibility in the first round and the increase in the same in the second round with dimensions. Furthermore, the amount of white noise that can be added to a maximally entangled state so that it has two rounds of the violation decreases with the dimension, while it does not appreciably change for the maximally violating states.
DOI: 10.1103/PhysRevA.109.062227
Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.109.062227
