The discussion of qubit for quantum computation in quantum dots technology
is presented. The state-of-the-art structure of multi-electron dot is consi
dered and the appropriate quasi-two-level system is suggested employing the
singlet-triplet transition in the presence of magnetic field. The methods
of qubit rotation (the write procedure) as well as two-qubit operations, as
controlled-NOT, in vertically stacked dots system are analysed.