Wick's symbol approach to the impurity bound fröhlich polaron

Upper bound estimates for the ground state energy of quantized Fröhlich's model of the free and impurity bound Landau-Pekar polaron were derived by means of a variational method based on the Wick symbol formalism and the theory of coherent states. The bounds so obtained are valid at arbitrary electron-phonon coupling strength. The proposed approach allows for generalization to the case of the Fröhlich polaron model in external magnetic Held as well as to various quantum models of polarons confined by external potentials, thus forming polaronic quantum dots.