Generation of high-fidelity four-photon cluster state and quantum-domain demonstration of one-way quantum computing

Phys Rev Lett. 2008 May 30;100(21):210501. doi: 10.1103/PhysRevLett.100.210501. Epub 2008 May 27.


We experimentally demonstrate a simple scheme for generating a four-photon entangled cluster state with fidelity over 0.860+/-0.015. We show that the fidelity is high enough to guarantee that the produced state is distinguished from Greenberger-Horne-Zeilinger, W, and Dicke types of genuine four-qubit entanglement. We also demonstrate basic operations of one-way quantum computing using the produced state and show that the output state fidelities surpass classical bounds, which indicates that the entanglement in the produced state essentially contributes to the quantum operation.