Generation of high-fidelity four-photon cluster state and quantum-domain demonstration of one-way quantum computing.
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.
Tokunaga
Yuuki
Y
Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan. tokunaga.yuuki@lab.ntt.co.jp
Kuwashiro
Shin
S
Yamamoto
Takashi
T
Koashi
Masato
M
Imoto
Nobuyuki
N