Entangled Bell and Greenberger-Horne-Zeilinger States of Excitons in Coupled Quantum Dots

We show that excitons in coupled quantum dots are ideal candidates for reliable preparation of entangled states in solid-state systems. An optically controlled exciton transfer process is shown to lead to the generation of Bell and Greenberger-Horne-Zeilinger states in systems comprising two and three coupled dots, respectively. The strength and duration of selective light pulses for producing maximally entangled states are identified by both analytic and full numerical solution of the quantum dynamical equations. Experimental requirements to build such entangled states are discussed.