Conjugated Conducting Polymers

absorption addition applied approach approximation atoms band behaviour bipolarons bond bond alternation calculations carriers chain charged chemical concentration conductivity configuration conjugated polymers contribution correlation corresponding Coulomb Coulomb interactions coupling decreases defects density dependence described determined dimerization discussed dopant doping effects electron electron-electron energy excitations expected experimental experiments field finite frequency function give ground Hamiltonian hopping Hubbard important increase indicated interactions interpretation involving lattice leads length Lett limit localized magnetic materials measurements metallic methods modes molecules motion neutral nuclear observed obtained optical pair parameter peak phonon Phys Physics polarons polyacetylene polyenes polymers position properties range relaxation resonance respect samples Sect separation shift shown shows similar single soliton spectra spectrum spin structure studies symmetry Synth temperature theoretical theory trans-(CH transition units valence values whereas