Control of molecular systems with very few phases

Constructive procedures, which make no use of optimization or iterative cal culations, for the control of molecular systems with sinusoidal pulses are described. The main contribution is to demonstrate that the phases of these pulses can be taken to be one out of a very small list of phases. One of t his small list can be taken to be any desired value. In addition. the pulse area of these fields can also be bounded by any desired bound. Thus. while the rotating wave approximation is the context in which the above results are obtained, the class of atoms/molecules to which the methodology applies is very wide. (C) 2001 Elsevier Science B.V. All rights reserved.