2004/02/29 by J. L. O'Brien, G. J. Pryde, A. Gilchrist +4 · 3 citations
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physrevlett.93.080502
published as Phys.Rev.Lett.93:080502,2004 · 4 pages, 2 figures. v2 contains new data corresponding to improved gate operation. Figure quality slightly reduced for arXiv
arxiv created 2004/08/16 · arxiv updated 2009/12/01
We demonstrate complete characterization of a two-qubit entangling process - a linear optics controlled-NOT gate operating with coincident detection - by quantum process tomography. We use maximum-likelihood estimation to convert the experimental data into a physical process matrix. The process matrix allows accurate prediction of the operation of the gate for arbitrary input states, and calculation of gate performance measures such as the average gate fidelity, average purity and entangling capability of our gate, which are 0.90, 0.83 and 0.73, respectively.