A simple effective Hamiltonian for the electron-phonon coupling in the conjugated polymers is derived from the Su-Schrieffer-Heeger model with quantized lattice motions. Phonons correspond to lattice quantum fluctuations around the dimerized positions. Both acoustic and optical modes are considered. The energy-momentum relation for the polaron is calculated variationally, with the aid of Lee-Low-Pines transformation. The discrete translational invariance of an ideal conjugated polymer is explicitly enforced. Analytical expression for the polaron effective mass (Formula presented) is obtained. (Formula presented) turns out to be, in general, much larger than the conduction-band effective mass.
|Number of pages||7|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 1 Jan 1997|