Fiber-Optics Implementation of an Asymmetric Phase-Covariant Quantum Cloner
Lucie Bartůšková, Miloslav Dušek, Antonín Černoch, Jan Soubusta, Jaromı́r Fiurášek · Physical Review Letters · 2007
We present the experimental realization of optimal symmetric and asymmetric phase-covariant 1-->2 cloning of qubit states using fiber optics. The state of each qubit is encoded into a single photon which can propagate through two optical fibers. The operation of our device is based on one- and two-photon interference. We have demonstrated the creation of two copies for a wide range of qubit states from the equator of the Bloch sphere. The measured fidelities of both copies are close to the theoretical values and they surpass the theoretical maximum obtainable with the universal cloner.