Spintronic Effects in Semiconductor Nanostructures

We report progress in calculations of spin coherence and spin transport properties in nanoscale geometries, including calculations of g-factors in quantum dots, exchange interactions in Si/Ge quantum dots, tuning of spin coherence times for electron spin, tuning of dipolar magnetic fields for nuclear spin, spontaneous spin polarization generation and new designs for spin-based teleportation and spin transistors. Our new proposal for electron-spin based teleportation is mediated by single photons and does not require correlated photon detection (Bell detection). We find that electric transport in nonmagnetic semiconductors is unstable to the formation of spin- polarized packets at room temperature. We also predict that orbital angular momentum quenching in quantum dots will drive g factors closer to 2 than previously expected. These calculations may be of use in semiconductor spintronic devices or quantum computation.