Average fidelity of qubit transfer through a linear spin-S channel for N=4, 5, 6

Abstract

We consider the transfer of an arbitrary qubit state through a linear spin chain for N=4, 5, and 6 spins, each with a spin-S channel. We calculate the average fidelity between the arbitrary initial state of the qubit at one end and the time evolved qubit state at the opposite end of the chain. We show that increasing the quantum number S of the channel spins allows attaining near perfect state transfer at an earlier time for the isotropic exchange case. We also show that an opposite effect is observed in the anisotropic case.