TEMPERATURE-DEPENDENCE OF STRONGLY COUPLED SURFACE POLARON IN POTASSIUM-IODIDE SEMIINFINITE POLAR CRYSTAL

Temperature dependences of the effective Hamiltonian and the renormali zed mass of surface polaron, for which the electron is strongly couple d with the surface-optical(SO) phonons but weakly or intermediately co upled with the bulk longitudinal-optical (LO) phonons, are derived. Te mperature dependences of the self-energy and the renormalized mass of the polaron for the polar crystal of potassium iodide are evaluated as a function of the depth from the crystal surface. Results of our calc ulation indicate that the self-trapping energy increases for strong el ectron-SO-phonon coupling but decreases for weak electron-LO-phonon co upling with temperature.