  We present a set of concrete and realistic ideas for the implementation of a
small-scale quantum computer using electron spins in lateral GaAs/AlGaAs
quantum dots. Initialization is based on leads in the quantum Hall regime with
tunable spin-polarization. Read-out hinges on spin-to-charge conversion via
spin-selective tunneling to or from the leads, followed by measurement of the
number of electron charges on the dot via a charge detector. Single-qubit
manipulation relies on a microfabricated wire located close to the quantum dot,
and two-qubit interactions are controlled via the tunnel barrier connecting the
respective quantum dots. Based on these ideas, we have begun a series of
experiments in order to demonstrate unitary control and to measure the
coherence time of individual electron spins in quantum dots.
