Copying of Entangled States and the Degradation of Correlations
Paweł Masiak, P. L. Knight · Fortschritte der Physik · 2001
We investigate the degree to which entanglement survives when a correlated pair of two-state systems are copied to two or more copies using either local or non-local processes. We show how the copying process degrades the entanglement, due to a residual correlation between the copied output and the copying machine (itself made of qubits).