Spin-polarized current in semimagnetic semiconductor heterostructures

A semimagnetic semiconductor tunneling device is proposed as a spin filter. This device, which gives spin-polarized electron current, is obtained by c hoosing different layers of II-VI compounds, with magnetic moments of subst itutional ions of Mn2+ in some of the layers. We present a theoretical calc ulation of the tunneling current for the device, in which electron spin-fli p scattering produced by the thermal fluctuations of the magnetic moments i s accounted for and found to be inefficient in depolarizing the current. A different system is also investigated to show more clearly the effects of s pin-flip scattering on the tunneling current. (C) 1999 American Institute o f Physics. [S0003-6951(99)02519-X].