Magnetoresistance of random double-chain systems

The transport properties of double-chain systems with random interchain couplings in the presence of a magnetic field are studied theoretically by the use of an exact self-consistent recursion method and the Landauer's formula. Each of the chains is either pure or doped with impurities. Our results show that the magnetic field has either a delocalization or localization effect on electronic states depending on the type of the topological configuration of the system. Some structures exhibit a high positive magnetoresistance. The calculated magnetic-field and temperature dependence of the conductance are compared with experimental data of highly conducting polymers.