Exciton in a slab of polar crystal

Abstract

In this paper, a weak-coupling exciton-phonon system in a polar-crystal slab is studied. A unitary transformation to the Hamiltonian is carried out, the effective Hamiltonian of the exciton-phonon system is obtained by variational technique. The variation of the self-energy and the induced potential with the thickness of the slab is calculated. Eventually, the ground-state and the first-excited-state energy of the exciton in the slab for different thicknesses of the slab are calculated by the variational method.