3. Experimental Demonstration of Teleportation Only the following states can be detected unambiguously: Furthermore, it is easier to detect since it is the only case in which the photons go to different detectors. if both D1 and D2 click, Alice has As we have seen, if Alice measures , Bob’s photon’s state is
4. Experimental Demonstration of Teleportation In actual test P was set to +45 0 and Bob set his beam splitter to +/-45 0 Teleportation would than be demonstrated by coincidence on detectors D1D2D4 and no coincidence on D1D2D3
5. Experimental Demonstration of Teleportation If #1 and #3 arrive at different times – no interference and D1 and D2 click simultaneously with 50% prob. In this case no teleportation occurs, thus D3 and D4 click with 50% prob. If #1 and #2 arrive to BS at the same time interference can occur and Alice can make Bell-state measurement. We would then expect the coincidence rate D1D2D3 to drop to zero, with D1D2D4 remaining at 25% . The probability for D1D2D3 or D1D2D4 coincidence is 25%
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9. Single-Photon interference experiments When there is no path length difference, only one detector clicks When the path length difference is larger than coherence length coincidence on D1 and D2 occurred with 50%