title: Crossover from super- to subdiffusive motion and memory effects in crystalline organic semiconductors.
abstract: The transport properties at finite temperature of crystalline organic semiconductors are investigated, within the Su-Schrieffer-Heeger model, by combining an exact diagonalization technique, Monte Carlo approaches, and a maximum entropy method. The temperature-dependent mobility data measured in single crystals of rubrene are successfully reproduced: a crossover from super- to subdiffusive motion occurs in the range 150≤T≤200  K, where the mean free path becomes of the order of the lattice parameter and strong memory effects start to appear. We provide an effective model, which can successfully explain features of the absorption spectra at low frequencies. The observed response to slowly varying electric field is interpreted by means of a simple model where the interaction between the charge carrier and lattice polarization modes is simulated by a harmonic interaction between a fictitious particle and an electron embedded in a viscous fluid.
authors.affiliation: SPIN-CNR and Dipartimento di Fisica, Università di Napoli Federico II, I-80126 Napoli, Italy.
authors.forename: G
authors.initials: G
authors.lastname: De Filippis
authors.affiliation: SPIN-CNR and Dipartimento di Fisica, Università di Napoli Federico II, I-80126 Napoli, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Cataudella
authors.affiliation: RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.
authors.forename: A S
authors.initials: AS
authors.lastname: Mishchenko
authors.affiliation: RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.|Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Nagaosa
authors.affiliation: SPIN-CNR Complesso Universitario di Monte S. Angelo, I-80126 Napoli, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Fierro
authors.affiliation: INFN, SPIN-CNR, and Dipartimento di Fisica, Università di Napoli Federico II, I-80126 Napoli, Italy.
authors.forename: A
authors.initials: A
authors.lastname: de Candia