  We present theory and calculations for coherent high-fidelity quantum control
of many-particle states in semiconductor quantum wells. We show that coupling a
two-electron double quantum dot to a terahertz optical source enables targeted
excitations that are one to two orders of magnitude faster and significantly
more accurate than those obtained with electric gates. The optical fields
subject to physical constraints are obtained through quantum optimal control
theory that we apply in conjunction with the numerically exact solution of the
time-dependent Schrodinger equation. Our ability to coherently control
arbitrary two-electron states, and to maximize the entanglement, opens up
further perspectives in solid-state quantum information.
