基于高保真度多光子纠缠源的量子关联实验研究

发布时间：2018-06-17 15:52

本文选题：“三明治”型纠缠源 + 多光子纠缠　；参考：《中国科学技术大学》2016年博士论文

【摘要】：对量子关联的研究一直是量子信息物理学的核心问题,其不仅有助于我们对量子理论的理解,而且量子关联也是实现量子信息方案的核心资源。比如量子纠缠是量子通信和量子计算的核心资源,量子非局域性是仪器无关量子信息方案的必要资源,量子相干性是量子精密测量的核心资源等。如今对两体系统的量子关联研究已经很成熟,然而对多体系统的量子关联还有很多问题没有搞清楚。对低量子位系统的量子模拟以及量子关联的研究,线性光学系统无疑是最便捷最成熟的实验平台。本文的主要内容包括：1.设计并实现了一种“三明治”型纠缠光子源,这种新型纠缠源具有更高的亮度和符合效率,利用该纠缠源我们制备出了高保真度的六光子GHZ态(88.4%),并首次验证了六光子GHZ类型的非局域性,刷新了实验中非局域光子个数的记录。此外我们还提出了多体GHZ悖论的普适构造方法。2.对原有制备四光子线性簇态的方案进行了改进,大幅度提高了态制备的成功几率,并在实验中对该方案进行了验证,此外我们的方案还可以扩展到制备任意长的簇态链。3.实验验证了两类三粒子纠缠态在信号不可超光速框架下的真多体非局域性。在二值输入二值输出的情况下,这两类态均很难展示出Svetlichny定义的真多体非局域性。因此从资源角度讲,新定义的真多体非局域性适用范围更广。4.在量子相干性方面开展的两项工作：实验验证一种不需要量子态层析,通过对两份未知态拷贝做贝尔基测量便可得到其量子相干性下限的方案；实验验证了一类复合系统在遭受特定方向的马尔科夫噪声时其相干性仍然保持的现象。
[Abstract]:The study of quantum correlation has always been the core of quantum information physics, which is not only helpful to our understanding of quantum theory, but also the core resource to realize quantum information solution. For example, quantum entanglement is the core resource of quantum communication and quantum computation, quantum nonlocality is the essential resource of instrument-independent quantum information scheme, quantum coherence is the core resource of quantum precision measurement. The research on quantum correlation of two-body system is very mature. However, there are still many problems about quantum correlation of multi-body system. The linear optical system is undoubtedly the most convenient and mature experimental platform for the study of quantum simulation and quantum correlation of low quantum bit systems. The main contents of this paper include: 1. A sandwich type entangled photon source is designed and implemented. The new entangled source has higher luminance and coincidence efficiency. Using this entanglement source, we have prepared a high fidelity six-photon GHz state of 88.4g, and verified the nonlocality of the six-photon GHz for the first time, and refreshed the record of the number of non-local photons in the experiment. In addition, we propose a universal construction method of multibody GHz paradox. The original scheme of preparing four-photon linear cluster states is improved, and the success probability of state preparation is greatly improved. The scheme is verified in experiments. In addition, our scheme can also be extended to the preparation of arbitrary length cluster state chain. 3. The experimental results show that the true multibody nonlocality of two kinds of three-particle entangled states is true under the frame of non-superluminal signal. In the case of binary input and binary output, it is difficult to show the true multibody nonlocality defined by Svetlichny. Therefore, in terms of resources, the new definition of true multibody nonlocality is more widely used. 4. 4. Two works on quantum coherence have been carried out: experimental results show that a scheme for obtaining the lower limit of quantum coherence can be obtained by measuring two copies of unknown states by Belky without quantum state chromatography; The experimental results show that the coherence of a class of composite system is still maintained when it is subjected to Markov noise in a certain direction.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O431.2

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