Elementary Excitations of a Linearly Conjugated Diatomic Polymer

The low-lying particlelike excitations of a model linearly conjugated diatomic polymer, (/A=B)/_x, are found to be pairs of either spin-0 or spin- 1/2 solitons with irrational charge values. The charge values and excitation energies are calculated as functions of the difference of the energy levels of the atomic p orbitals of the two atomic constitutents of the unit cell. The phonon spectrum of the uniform polymer is also calculated.