High-Probability Quantum State Transfer in the Alternating Open Chains   of 1/2 Spins with XY Hamiltonian
  This paper concerns the problem of non-ideal state transfer along the alternating open chain of spins $s=1/2$ with XY Hamiltonian. It is found that the state transfer along the chain with even number of spins $N$ ($N=4,6,8$) may be realized with high probability. Privilege of even $N$ in comparison with odd $N$ is demonstrated. 
E.I.Kuznetsova and A.I.Zenchuk