Observation of spin-selective tunneling in SiGe nanocrystals
  Spin-selective tunneling of holes in SiGe nanocrystals contacted by normal-metal leads is reported. The spin selectivity arises from an interplay of the orbital effect of the magnetic field with the strong spin-orbit interaction present in the valence band of the semiconductor. We demonstrate both experimentally and theoretically that spin-selective tunneling in semiconductor nanostructures can be achieved without the use of ferromagnetic contacts. The reported effect, which relies on mixing the light and heavy holes, should be observable in a broad class of quantum-dot systems formed in semiconductors with a degenerate valence band. 
G. Katsaros, V. N. Golovach, P. Spathis, N. Ares, M. Stoffel, F.   Fournel, O. G. Schmidt, L. I. Glazman, and S. De Franceschi
cond-mat.mes-hall