  Semiconductor nanocrystals are being used as hosts to trap and manipulate
single spins. Spins in nanocrystals can have different properties than their
bulk counterparts, owing both to quantum confinement and surface effects. We
will show that spins can be generated in nanocrystals by the insertion of
impurities, either magnetic or not, or by magnetic polarons present at dangling
bonds at their surfaces. This chapter reports theoretical contributions to this
field, where the Density Functional Theory is used to simulate these
functionalized nanocrystals.
