Quantum control of charge carriers in quantum wells

We present theoretical studies of the quantum control of charge carriers in a direct-current-blase (DC-biased) asymmetric double quantum well (ADQW). The objective in this work is to find the laser pulse that drives an electr onic wave packet to maximum overlap with a target distribution in a chosen well at a chosen time. We use a genetic algorithm to determine the optimal parameters of the excitation pulses. The robustness of the control is analy zed with respect to the magnitude of the DC field, and two types of defects in the ADQW potential profile, a point defect and a notch. Ln all cases st udied, the genetic algorithm is able to reoptimize the laser field to achie ve the desired objective. Finally, we consider the effects of coupling the ADQW to a harmonic bath. We find that a coupling large enough to distort th e effective potential significantly does not eliminate the control. Our res ults indicate that control in the ADQW is quite robust, which should make i t a favorable system for further experimental study. (C) 2000 John Wiley gr Sons, Inc.