Resilience to decoherence of the macroscopic quantum superpositions generated by universally covariant optimal quantum cloning
Nicolò Spagnolo, Fabio Sciarrino, F. De Martini
We show that the quantum states generated by universal optimal quantum cloning of a single photon represent a universal set of quantum superpositions resilient to decoherence. We adopt the Bures distance as a tool to investigate the persistence of quantum coherence of these quantum states. According to this analysis, the process of universal cloning realizes a class of quantum superpositions that exhibits a covariance property in lossy configuration over the complete set of polarization states in the Bloch sphere.
arXiv:1003.0831•Physical Review A•Sep 27, 2010•5 citations