A NEW VARIATIONAL CALCULATION FOR N-DIMENSIONAL POLARONS IN THE STRONG-COUPLING LIMIT

A novel variational approach is presented for the calculation of the g round-state energy of the polaron in arbitrary N dimensions in the str ong-coupling limit By using the phonon coherent state to represent the wavefunction of phonons, a self-consistent integrodifferential equati on for the electron wavefunction is derived. The calculated results of the ground-state energy for N = 1, 2 and 3 agree well with the best r esults in the literature. It is also found that, for arbitrary N, the present results are less than the Feynman path integral ones by small percentages. It is proposed that this approach should be universal for systems involving polarons in the strong-coupling regime.