论文标题
通过在NMR量子处理器上重建相关张量来对多方纠缠的分类和测量
Classification and measurement of multipartite entanglement by reconstruction of correlation tensors on an NMR quantum processor
论文作者
论文摘要
我们介绍了将三量纯状态分类为不同的纠缠类别的协议，并将其在NMR量子处理器上实施。该协议的设计方式使得实验对状态进行分类的实验还可以测量该州存在的纠缠量。分类需要使用13个操作员对相关矩阵进行实验重建。相关矩阵的等级提供了将状态分类为五个类别之一的标准，即可分离，可分开，可分配（三种类型），并真正纠缠（两种类型，GHz和W）。为了量化纠缠，定义了使用相同的13个操作员，定义了该函数，该函数可以测量国家存在的全球纠缠。对于可分离状态而言，全球纠缠为零，否则为非零。我们通过对从六个不等于的（在随机的本地操作和经典通信）类中对三个Qubits选择的状态进行实施来证明该协议的功效。我们还对从三分之一纯国的状态空间随机选择的状态实施了协议。
We introduce a protocol to classify three-qubit pure states into different entanglement classes and implement it on an NMR quantum processor. The protocol is designed in such a way that the experiments performed to classify the states can also measure the amount of entanglement present in the state. The classification requires the experimental reconstruction of the correlation matrices using 13 operators. The rank of the correlation matrices provide the criteria to classify the state in one of the five classes, namely, separable, biseparable (of three types), and genuinely entangled (of two types, GHZ and W). To quantify the entanglement, a concurrence function is defined which measures the global entanglement present in the state, using the same 13 operators. Global entanglement is zero for separable states and non-zero otherwise. We demonstrate the efficacy of the protocol by implementing it on states chosen from each of the six inequivalent (under stochastic local operations and classical communication) classes for three qubits. We also implement the protocol on states picked at random from the state space of three-qubit pure states.
