Figure 1

Evolution of concurrence (solid line) and Schmidt number (dashed line) as one party of the maximally entangled state $|\Phi ⟩=\sum _{n=1}^d|n⟩|n⟩/\sqrt{d}$, ($d=5$) passes through a depolarizing channel with rate $\Gamma$ (resulting in an isotropic state). The initial decay of entanglement is well approximated (linearly) by the entanglement at time 0 [$C(0)$] and when the Schmidt number drops for the first time [here from 5 to 4, with the initial entanglement reduced by a fraction $1/(d-1)$, from 1 to $3/4$], which is exactly when $G$-concurrence vanishes.Reuse & Permissions