  We review our recent work addressing various theoretical issues in spin-based
quantum dot quantum computation and quantum information processing. In
particular, we summarize our calculation of electron exchange interaction in
two-electron double quantum dots and multi-electron double dots, and discuss
the physical implication of our results. We also discuss possible errors and
how they can be corrected in spin-based quantum dot quantum computation. We
critically assess the constraints and conditions required for building
spin-based solid state quantum dot quantum computers.
