  We review our work on the interplay between non-resonant gates and solid
state environment in various solid state quantum computer architectures and the
resulting gate errors. Particular, we show that adiabatic condition can be
satisfied in small quantum dots, while higher energy excited states can play
important role in the evolution of a Cooper-pair-box based quantum computer
model. We also show that complicated bandstructure such as that of Si can pose
a severe gate control problem.
