Lee Sang Min, Choi Sang-Kyung, Park Hee Su
Korea Research Institute of Standards and Science, Daejeon 305-340, South Korea.
Opt Express. 2013 Jul 29;21(15):17824-30. doi: 10.1364/OE.21.017824.
We propose a multi-photon interferometer with a generalized C-SWAP operation that can estimate Tr[ρ(1)ρ(2)···ρ(n)], a nonlinear functional of n photonic density matrices. The scheme is demonstrated for three single-photon states whose overlap is experimentally measured as the interference visibility of a control qubit encoded into photonic paths. The validity of this method is verified by comparing the visibility with the results of Hong-Ou-Mandel experiments.
我们提出了一种具有广义C-SWAP操作的多光子干涉仪，它可以估计Tr[ρ(1)ρ(2)···ρ(n)]，这是n个光子密度矩阵的非线性函数。该方案针对三个单光子态进行了演示，其重叠通过实验测量为编码在光子路径中的控制量子比特的干涉可见度。通过将可见度与Hong-Ou-Mandel实验结果进行比较，验证了该方法的有效性。
