Selective spin coupling through a single exciton

A technique for performing a conditional phase gate between two spin qubits in adjacent semiconductor quantum dots through delocalized single exciton state, formed through Förster interaction, was analyzed. Two resonant quantum dots containing a single excess conduction band electron whose spin embodies the qubit were used. It was observed that both gates have performed to a good fidelity with semiconductor and laser technology. It was also observed that the ratio of exciton gate decay to spin qubit decoherance times can decrease the threshold fidelity required by fault tolerant quantum computation (FTQC).