Coherent control of localization, entanglement, and state superpositions in a double quantum dot with two electrons

We have recently proposed a quantum control method based on the knowledge of the energy spectrum as a function of an external control parameter [Phys. Rev. Lett. {\bf 99}, 036806 (2007)]. So far, our method has been applied to connect the ground state to target states that were in all cases energy eigenstates. In this paper we extend that method in order to obtain more general target states, working, for concreteness, with a system of two interacting electrons confined in semiconductor double quantum wells. Namely, we have shown that the same basic method can be employed to obtain localization, entanglement, and general superpositions of eigenstates of the system.