Surface diffusion and spin polarization: Two dimensional CIDEP

An asymptotic Green’s function method that proved successful for spin polarization–diffusion processes in bulk solution is extended to similar processes on surfaces. An approximate solution indicates that the dependence on the exchange interaction is similar in two and three dimensional processes, the dependence on time and magnetic interactions, dissimilar. The latter difference is attributed to a fundamentally different feature of two dimensional diffusion-controlled processes: two particles undergoing random walk motion that have collided once are certain to collide again.