Experimental determination of entanglement by a projective measurement
Stephen Patrick Walborn, P. H. Souto Ribeiro, L. Davidovich, Florian Mintert, Andreas Buchleitner · Physical Review A · 2007
We describe a method in which the entanglement of any pure quantum state can be experimentally determined by a simple projective measurement, provided the state is available in a twofold copy. We propose implementations of this approach for various systems and discuss in detail its first experimental realization, which employed twin photons entangled in two degrees of freedom, prepared in identical polarization and momentum states. We analyze the effect of errors due to imperfect state preparation.