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Experimental Realization of a Photonic Bell-State Analyzer

Philip Walther·Anton Zeilinger
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Abstract

Efficient teleportation is a crucial step for quantum computation and quantum networking. In the case of qubits, four different entangled Bell states have to be distinguished. We have realized a probabilistic, but in principle deterministic, Bell-state analyzer for two photonic quantum bits by the use of a nondestructive controlled-NOT gate based on entirely linear optical elements. This gate was capable of distinguishing between all of the Bell states with higher than 75% fidelity without any noise substraction due to utilizing quantum interference effects.

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Philip Walther, Anton Zeilinger. 2005-07-19. Experimental Realization of a Photonic Bell-State Analyzer. https://doi.org/10.1103/physreva.72.010302

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