Intense field effects on shallow donor impurities in graded quantum wells

Abstract

Using a variational method and within the effective mass approximation, we calculate the laser-field dependence of binding energy and the polarizability of shallow-donor impurities in graded quantum wells under an external static electric field. We have shown that, in the graded quantum well structures, not only the 'dressed' potential but also the direction of the external electric field parallel to the growth direction play very important roles in the determination of the binding energy and the polarizability of a hydrogenic impurity.