Crucial role of decoherence for electronic transport in molecular wires: Polyaniline as a case study

CARLOS J. CATTENA; RAÚL A. BUSTOS-MARÚN; HORACIO M. PASTAWSKI

PHYSICAL REVIEW B - SOLID STATE

American Physical Society

Lugar: Ridge; Año: 2010 vol. 82, p. 14420 - 14420

0556-2805

Crucial role of decoherence for electronic transport in molecular wires: Polyaniline as a case study Carlos J. Cattena, Raúl A. Bustos-Marún, and Horacio M. Pastawski Phys. Rev. B 82, 144201 (2010) In this work we attempt to elucidate the nature of conductivity in polymers by taking the acid-base doped polyaniline
PAni polymer. We evaluate the PAni conductance by using realistic ab initio parameters andincluding decoherent processes within the minimal parametrization model of D’Amato-Pastawski. In contrast to general wisdom, which associates the conducting state with coherent propagation in a periodic polaroniclattice, we show that decoherence can account for high conductance in the strongly disordered bipolaronic lattice. Hence, according to our results, there is no need of considering a mix model of “conducting” polaronic lattice islands separated by “insulating” bipolaronic lattice strands as is usually assumed for PAni. We find that without dephasing events, even very short strands of bipolaronic lattices are not able to sustain electronic transport. We also include a discussion of specific mechanisms that should be involved in decoherence rates of PAni and relate them with Marcus-Hush theory of electron transfer.