Model for ballistic spin-transport in ferromagnet/two-dimensional electron gas/ferromagnet structures

The spin dependent conductance of a ferromagnet/two-dimensional electron gas/ferromagnet structure is theoretically examined in the ballistic transport regime. It is shown that the spin signal can be improved considerably by making use of the spin filtering effect of a barrier at the ferromagnet/two-dimensional electron gas interface. For sufficiently short semiconductor layers interference effects can result in an additional increase of the spin signal.