GROUND-STATE DESCRIPTION FOR POLARONS IN PARABOLIC QUANTUM-WELLS

Within the framework of Feynman-Haken variational path integral theory , for the first time, we calculate the ground-state energy of the elec tron and longitudinal-optical phonon system in parabolic quantum wells with respect to a general potential. We propose a simple expression f or the Feynman energy, and compare it with those obtained by the secon d-order Rayleigh-SchrGdinger perturbation theory and Landau-Pekar stro ng-coupling theory. It is shown both analytically and numerically that the results obtained from Feynman-Haken variational path integral the ory can be better than those from the other two theories. We also find in numerical calculations that the binding energy of polarons becomes monotonically stronger as the effective well depth decreases in the w hole coupling regime. More interestingly, the localization, which is c aused by the effective potential, also can be perceived in the strong- coupling regime.