Experimental construction of optical multiqubit cluster states from Bell states
An‐Ning Zhang, Chao‐Yang Lu, Xiaoqi Zhou, Yu-Ao Chen, Zhi Zhao, Tao Yang, Jian-Wei Pan · Physical Review A · 2006
Cluster states serve as the central physical resource for one-way quantum computing. We here present an experimental demonstration of the efficient cluster-state construction scheme proposed by Browne and Rudolph. In our experiment, three-photon cluster states with high purity are created from two Bell states via a qubit ``fusion'' operation, showing a strong violation of a three-particle Mermin inequality of $\ensuremath{\mid}⟨A⟩\ensuremath{\mid}=3.10\ifmmode\pm\else\textpm\fi{}0.03$. In addition, the entanglement properties of the cluster states are examined under ${\ensuremath{\sigma}}_{z}$ and ${\ensuremath{\sigma}}_{x}$ measurements on a qubit. This scheme could be extended to any desired number of qubits and represents an essential step for the optical one-way quantum computation.