Strong-coupling theory of quasi-two-dimensional polarons

A strong-coupling theory of the polaron is developed to study the electron-phonon interaction in quantum-well structures consisting of strong polar crystals. By introducing a two-parameter trial wave function to take care of the strong anisotropy, the Landau-Pekar theory is extended to investigate polaronic effects in a quantum well. It is shown that the theory yields correct results in both the two-dimensional and three-dimensional limits. The ground-state properties of quasi-two-dimensional polarons are calculated as functions of the well width for two choices of the coupling constant .