Bipolaron singlet and triplet states in disordered conducting polymers

We emphasize the role of the dopant potential on the stability and magnetic properties of bipolarons in a conducting polymer. For this purpose the singlet and the triplet states of a bipolaron have been calculated within an adiabatic deformable continuum model including short-range Coulomb repulsions between electrons and attractions by the ionized dopants. We derive a new interpretation of the spin-charge relation and of the so-called Curie and Pauli contributions to the susceptibility of disordered conducting polymers.