Experimental realization of a photonic Bell-state analyzer

Philip Walther, Anton Zeilinger
2005 Physical Review A. Atomic, Molecular, and Optical Physics  
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
more » ... oise substraction due to utilizing quantum interference effects.
doi:10.1103/physreva.72.010302 fatcat:thitpdpvxvgfdpys6z52t5gloq