The conformation of conducting polymer chains: Hubbard polymers
  The conformational and electronic properties of conducting flexible random and self-avoiding walk polymer chains are under investigation. A Hamiltonian for conjugated flexible polymers is introduced and its physical consequences are presented. One important result is that the electronic degrees of freedom greatly affect the conformational statistics of the walks and vice versa. The electronic degrees of freedom extend the size of the chain. The end-to-end distance behaves as $R\propto L^{\nu}$ with $\nu=(d+1)/(d+2)$, where $d$ is the spatial dimension. 
M.Otto and T.A.Vilgis