Observable Entanglement Measure for Mixed Quantum States

Florian Mintert, Andreas Buchleitner
2007 Physical Review Letters  
We show how an unknown mixed quantum state's entanglement can be quantified by a suitable, local parity measurement on its two-fold copy.
doi:10.1103/physrevlett.98.140505 pmid:17501257 fatcat:wav2izv3zzbh3ejufo6xvmp3rq