We propose a fast optically induced two-qubit \textsc{c-phase} gate between
two resident spins in a pair of coupled quantum dots. An excited bound state
which extends over the two dots provides an effective electron-electron
exchange interaction. The gate is made possible by the electron-hole exchange
interaction, which isolates a single transition in the system. When combined
with appropriate single qubit rotations, this gate generates an entangled state
of the two spins
