Positive magnetoresistance in quasi-one-dimensional conductors

We present here a simple qualitative model that interpolates between the high-and low-temperature properties of quasi-one-dimensional conductors. At high temperatures we argue that transport is governed by inelastic scattering while at low temperatures the conductance decays exponentially with the electron dephas ing length. The crossover between these regimes occurs at the temperature at which the elastic and inelastic scattering times become equal. This model is shown to be in quantitative agreement with the organic conductor TTT2I3-delta. Within this model, we also show that on the insulating side, the positive magnetoresistance of the form (H/T)(2) observed in TTT2I3-delta and other quasi-one-dimensional conductors can be explained by the role spin-flip scattering plays in the electron dephasing rate.