Ground state energy of the fröhlich polaron as a function of dimensionality and the phonon coupling strength

Abstract

We use the trial polaron wave function introduced by Devreese et al. [1] to estimate the ground state energies of the Fröhlich polaron over a broad range of the phonon coupling strength by a variational approach. We calculate the binding energy of the polaron as a function of dimensionality interpolating between two and three dimensions. We compare these results with the outcomes obtained by the Strong and Weak Coupling Theories and conclude that in the strong coupling regime, the present work leads to a significantly improved upper bound for the ground state energy.