THE TEMPERATURE-DEPENDENCE OF THE N-DIMENSIONAL POLARON

The Lee-Low-Pines-like intermediate method is adopted to study the pro perties of a slow-moving optical polaron in an N-dimensional polar cry stal at a finite temperature. The analytical expressions for the inter nal energy and effective mass of the polaron for a certain momentum K( p) are derived using the approximation that the thermophonon number is independent of the wavevector. The numerical results obtained by cons idering the dependence of the thermophonon number on the wavevector ar e also obtained. It is shown that the temperature effect of the polaro n diminishes with increasing dimensionality.