Ground state features of the Frohlich model

摘要

Following the ideas behind the Feynman approach, a variational wave functionis proposed for the Fr\"ohlich model. It is shown that it provides, for anyvalue of the electron-phonon coupling constant, an estimate of the polaronground state energy better than the Feynman method based on path integrals. Themean number of phonons, the average electronic kinetic and interactionenergies, the ground state spectral weight and the electron-lattice correlationfunction are calculated and successfully compared with the best availableresults.