Quantum computation with quantum dots and terahertz cavity quantum electrodynamics

A quantum computer is proposed in which information is stored in the two lowest 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-NOT operation is estimated to be much shorter than the time for an electron to decohere by emitting an acoustic phonon.