Ground state description of impurity-bound polarons in parabolic quantum wells

Within the framework of Feynman-Kaken path integral theory, we calculate th e ground-state energy of a polaron in parabolic quantum wells in the presen ce of a Coulomb potential. It is shown that the polaronic correction of the ground state is more sensitive to the electron-(LO)phonon coupling constan t than the Coulomb binding parameter, and it monotonically increases with t he decreasing effective well width. Moreover, we compare our results to tho se obtained by Landau-Pekar variational scheme. We find that the Feynman-Ha ken method gives better results than the Landau-Pekar variational method. I t is demonstrated that the result from Landau-Pekar variational method is j ust a special case of those from Feynman-Haken method. We also apply our ca lculations to several polar semiconductor quantum wells and find that the p olaronic correction can be considerably large. Moreover, the localization o f the system is found to be strengthened with the increasing of the electro n-phonon coupling constant and the Coulomb binding parameter.