Coherent Control of a Simple Quantum System

The quantum dynamics of a three-level Vee-system can be controlled by using two single-mode cw lasers. The dc component of the probability for finding a specific state in laser fields can be obtained by matching the intensities, phases and detunings of the lasers to relevant eigenvalues of the quantum system. The selectivity of control does not depend strongly on the laser intensities but the absolute amount of the product does strongly. There are generally three paths to reach such a dc component control and, at some points, two of them cross each other causing a near 100% control. The stability of the process to the fluctuation of the experiment was analyzed.