Department of Computer Science, College of Information Science and Technology, Jinan University, Guangzhou, 510632, China.
Department of Mathematics, College of Information Science and Technology, Jinan University, Guangzhou, 510632, China.
Sci Rep. 2017 May 16;7(1):1982. doi: 10.1038/s41598-017-02146-9.
Cluster states, whose model are a remarkably rich structure in measurement-based quantum computation, hold high degree of entanglement, while entanglement is very fragile during the process of transmission because of the inevitable interaction with the environment. We propose two entanglement concentration protocols for four-particle linear cluster states which and are susceptible to the decoherence and the imperfect communication setups. In the first protocol, POVM operators are introduced to maximize the success probability, and the second protocol is based on cross-Kerr nonlinearity which is utilized to check the parity between the original particle and the ancillary particle. Both of the protocols have their own advantages. The first one can be easily realized in experiment by linear optics, while the one with cross-Kerr nonlinearity reach more than 90% success probability by iteration. Since the wide application of cluster states, the two protocols are efficient and valuable to different fields of quantum communication.
簇态，其模型在基于测量的量子计算中具有非常丰富的结构，具有高度的纠缠，而纠缠在传输过程中由于与环境的不可避免的相互作用而非常脆弱。我们提出了两种适用于四粒子线性簇态的纠缠浓缩协议，这些协议容易受到退相干和不完善的通信设置的影响。在第一个协议中，引入了 POVM 算子来最大化成功概率，第二个协议基于交叉克尔非线性，用于检查原始粒子和辅助粒子之间的奇偶性。这两个协议都有各自的优点。第一个协议可以通过线性光学很容易地在实验中实现，而具有交叉克尔非线性的协议通过迭代可以达到超过 90%的成功概率。由于簇态的广泛应用，这两个协议对于量子通信的不同领域都是有效和有价值的。
