Wallnöfer J, Pirker A, Zwerger M, Dür W
Institut für Theoretische Physik, Universität Innsbruck, Technikerstr. 21a, A-6020, Innsbruck, Austria.
Sci Rep. 2019 Jan 22;9(1):314. doi: 10.1038/s41598-018-36543-5.
We introduce a repeater scheme to efficiently distribute multipartite entangled states in a quantum network with optimal scaling. The scheme allows to generate graph states such as 2D and 3D cluster states of growing size or GHZ states over arbitrary distances, with a constant overhead per node/channel that is independent of the distance. The approach is genuine multipartite, and is based on the measurement-based implementation of multipartite hashing, an entanglement purification protocol that operates on a large ensemble together with local merging/connection of elementary building blocks. We analyze the performance of the scheme in a setting where local or global storage is limited, and compare it to bipartite and hybrid approaches that are based on the distribution of entangled pairs. We find that the multipartite approach offers a storage advantage, which results in higher efficiency and better performance in certain parameter regimes. We generalize our approach to arbitrary network topologies and different target graph states.
我们引入一种中继器方案，以在量子网络中高效地分发具有最优缩放比例的多方纠缠态。该方案允许生成诸如不断增大尺寸的二维和三维簇态或任意距离上的GHZ态等图态，每个节点/通道的开销恒定且与距离无关。该方法是真正的多方方法，基于多方哈希的测量实现，这是一种纠缠纯化协议，它与基本构建块的局部合并/连接一起作用于一个大的系综。我们在局部或全局存储受限的情况下分析该方案的性能，并将其与基于纠缠对分发的二分法和混合方法进行比较。我们发现多方方法具有存储优势，这在某些参数范围内会带来更高的效率和更好的性能。我们将我们的方法推广到任意网络拓扑和不同的目标图态。
