Fig. 4: Absolute values of the density matrix elements for quantum states distributed via different types of channels.
From: Quantum channel correction outperforming direct transmission
a Maximally-mode-entangled state sent through an uncorrected quantum channel with L = 0.988 ± 0.001 added loss. b Same input state, but distributed through the error-corrected quantum channel with the nominal gain setting from Fig. 3, at which the observed concurrence was the highest. c, d and e, f same as a, b, but with L = 0.958 ± 0.001 and L = 0.903 ± 0.002, respectively.
