Spin diffusion on a linear spin polarised chain

We investigate the diffusion of a spin polarised projectile (silver atom) on a ferromagnetic spin polarised chain. The interaction between the projectile and the chain is described with a Heisenberg Hamiltonian which implied that we exclude the head-on collision which provokes strong electron exchange and fragmentation. We make a real time description of the spin of two interacting systems. We deduce from it the polarisation change of the projectile and the excitation in the chain versus the chain length, the impact parameter and the kinetic energy of the projectile. We analyse 3 different behaviors of the system according to whether the intra-chain excitation propagates slower or faster than the projectile.