A quantum computer is Proposed in which information is stored in the two lo
west electronic states of doped quantum dots (QD's). Many QD's are located
in a microcavity. A pair of gates controls the energy levels in each QD. A
controlled-NOT (C-NOT) operation involving any pair of QD's can be effected
by a sequence of gate-voltage pulses which tune the QD energy levels into
resonance with frequencies of the cavity or a laser. The duration of a C-NO
T operation;is estimated to be much shorter than the time for an electron t
o decohere by emitting an acoustic phonon. [S1050-2947(99)00311-X].