论文标题
与测量设备与非线性纠缠证人的结束漏洞
Closing loopholes of measurement-device-independent nonlinear entanglement witnesses
论文作者
论文摘要
纠缠见证人的概念构成了一种有用的技术，可以检测现实的量子设备中的纠缠。测量依赖性依赖性的非线性纠缠证人（MDI-NEWS）是一种纠缠证人，消除了对保证纠缠不清的测量设备正确对准的依赖，并且比其线性对应物检测到更多的纠缠状态。尽管该方法保证了独立于测量对准的纠缠，但由于其他漏洞，它们仍然容易出现错误的结果。在这里，我们研究了MDI新闻对实验中发生的两类故障的响应。在第一类中，研究了检测漏洞，其特征是丢失和测量结果的其他事件，并根据所执行的测量效率获得了保证纠缠的边界。在第二类中，我们研究了与MDI新场景中所需的其他量子输入相关的噪声。在这种情况下，确定了一种噪声，该噪声仍然允许MDI新闻保证纠缠。我们还表明，与其他量子输入中相同的噪声下的线性对应物相比，MDI-NEW较少或同样强大，尽管前者在噪音的无线性表情中检测到的无噪声状态比其线性表情更大的纠缠状态。
The concept of entanglement witnesses form a useful technique to detect entanglement in realistic quantum devices. Measurement-device-independent nonlinear entanglement witnesses (MDI-NEWs) are a kind of entanglement witnesses which eliminate dependence on the correct alignments of measurement devices for guaranteeing the existence of entanglement and also detect more entangled states than their linear counterparts. While this method guarantees entanglement independent of measurement alignments, they are still prone to serving wrong results due to other loopholes. Here we study the response of MDI-NEWs to two categories of faults occurring in experiments. In the first category, the detection loophole, characterized by lost and additional events of outcomes of measurements, is investigated, and bounds which guarantee entanglement are obtained in terms of the efficiency of measurement being performed. In the second category, we study noise associated with the sets of additional quantum inputs required in MDI-NEW scenarios. In this case, a type of noise is identified which still allows the MDI-NEWs to guarantee entanglement. We also show that MDI-NEWs are less or equally robust in comparison to their linear counterparts under the same noise in additional quantum inputs, although the former group detects a larger volume of entangled states in the noiseless scenario than their linear cousins.
