  As basic elements of the quantum computer - quantum bits (qubits) we offer
semiconductor quantum dots containing one electron each and consisting each of
two tunnel-connected parts. The numerical solution of a Schroedinger equation
with the account of Coulomb field of adjacent electrons shows, that in such
structures the realization of a full set of basic logic operations which are
necessary for fulfillment of quantum computations is possible. Durations of
one- and two-qubit operations versus qubit geometry are obtained. Decoherence
rates due to spontaneous emission of phonons and acoustic phonons (both
piezoelectric and deformation) are evaluated. Analysis of these rates shows the
offered qubit to be coherent enough to perform error correction procedures.
