论文标题
对称高斯州的纠缠措施和纠缠能力
Supremum of Entanglement Measure for Symmetric Gaussian States, and Entangling Capacity
论文作者
论文摘要
在这篇论文中，有两个主题：关于否定，量子操作的纠缠能力，以及对对称高斯国家的否定性。 正面部分转位（PPT）状态是量子信息中重要的一类状态。我们展示了一种计算纠缠能力的界限的方法，即量子操作可以产生的纠缠量，从消极的角度来看，是一种纠缠。发现纠缠能力的界限与非PPP（PPT保存）操作的方式相关联。可以定义量化操作或状态的纠缠能力/纠缠和ppt-的长度，并确定以PPT度为特征的几何形状。从长度界到相对纠缠的能力的距离，从而使几何形状具有更大的物理意义。 对于由置换对称的高斯模式组成的系统，通过识别有效状态的边界并进行必要的变量，可以分析显示任何两个块之间的对数负面效率（和否定性）的上限的存在和确切值。仅涉及可互换模式的总数和各个块的大小，此结果是一般且易于应用于此类状态的。
In this thesis there are two topics: On the entangling capacity, in terms of negativity, of quantum operations, and on the supremum of negativity for symmetric Gaussian states. Positive partial transposition (PPT) states are an important class of states in quantum information. We show a method to calculate bounds for entangling capacity, the amount of entanglement that can be produced by a quantum operation, in terms of negativity, a measure of entanglement. The bounds of entangling capacity are found to be associated with how non-PPT (PPT preserving) an operation is. A length that quantifies both entangling capacity/entanglement and PPT-ness of an operation or state can be defined, establishing a geometry characterized by PPT-ness. The distance derived from the length bounds the relative entangling capability, endowing the geometry with more physical significance. For a system composed of permutationally symmetric Gaussian modes, by identifying the boundary of valid states and making necessary change of variables, the existence and exact value of the supremum of logarithmic negativity (and negativity likewise) between any two blocks can be shown analytically. Involving only the total number of interchangeable modes and the sizes of respective blocks, this result is general and easy to be applied for such a class of states.
