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arXiv · 1305.0212

Experimental characterization of universal one-way quantum computing

B. A. Bell·M. S. Tame·A. S. Clark·R. W. Nock·W. J. Wadsworth·J. G. Rarity
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Abstract

We report the characterization of a universal set of logic gates for one-way quantum computing using a four-photon `star' cluster state generated by fusing photons from two independent photonic crystal fibre sources. We obtain a fidelity for the cluster state of 0.66 +/- 0.01 with respect to the ideal case. We perform quantum process tomography to completely characterize a controlled-NOT, Hadamard and T gate all on the same compact entangled resource. Together, these operations make up a universal set of gates such that arbitrary quantum logic can be efficiently constructed from combinations of them. We find process fidelities with respect to the ideal cases of 0.64 +/- 0.01 for the CNOT, 0.67 +/- 0.03 for the Hadamard and 0.76 +/- 0.04 for the T gate. The characterisation of these gates enables the simulation of larger protocols and algorithms. As a basic example, we simulate a Swap gate consisting of three concatenated CNOT gates. Our work provides some pragmatic insights into the prospects for building up to a fully scalable and fault-tolerant one-way quantum computer with photons in realistic conditions.

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B. A. Bell, M. S. Tame, A. S. Clark, R. W. Nock, W. J. Wadsworth, J. G. Rarity. 2013-05-01. Experimental characterization of universal one-way quantum computing. https://doi.org/10.1088/1367-2630%2F15%2F5%2F053030

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