Experimental Measurement of Multi-dimensional Entanglement via Equivalent Symmetric Projection

الأصل · EN

We construct a linear optics measurement process to determine the entanglement measure, named I-concurrence, of a set of 4 × 4 dimensional two-photon entangled pure states produced in the optical parametric down conversion process. In our experiment, an equivalent symmetric projection for the two-fold copy of single subsystem (presented by L. Aolita and F. Mintert, Phys. Rev. Lett. 97, 050501 (2006)) can be realized by observing the one-side two-photon coincidence without any triggering detection on the other subsystem. Here, for the first time, we realize the measurement for entanglement contained in bi-photon pure states by taking advantage of the indistinguishability and the bunching effect of photons. Our method can determine the I-concurrence of generic high dimensional bipartite pure states produced in parametric down conversion process.