Waveguide diffusion modes and slowdown of D'yakonov-Perel' spin relaxationin narrow two-dimensional semiconductor channels

We have shown that in narrow two-dimensional semiconductor channels the D'y akonov-Perel' spin relaxation rate is strongly reduced. This relaxation slo wdown appears in special waveguide diffusion modes which determine the prop agation of spin density in long channels. Experiments are suggested to dete ct the theoretically predicted effects. A possible application is a field e ffect transistor operated with injected spin current.