Three-dimensional effects on extended states in disordered models of polymers

Abstract

We study electronic transport properties of disordered polymers in the presence of both uncorrelated and short-range correlated impurities. In our procedure, the actual physical potential acting upon the electrons is replaced by a set of nonlocal separable potentials, leading to a Schrödinger equation that is exactly solvable in the momentum representation. We then show that the reflection coefficient of a pair of impurities placed at neighboring sites (dimer defect) vanishes for a particular resonant energy. When there is a finite number of such defects randomly distributed over the whole lattice, we find that the transmission coefficient is almost unity for states close to the resonant energy, and that those states present a very large localization length. Multifractal analysis techniques applied to very long systems demonstrate that these states are truly extended in the thermodynamic limit. These results reinforce the possibility to verify experimentally theoretical predictions about absence of localization in quasi-one-dimensional disordered systems.

16 pages, REVTeX 3.0, 5 figures on request from FDA ([email protected]). Submitted to Phys. Rev. B. MA/UC3M/09/94

References in corpus (4)

• Absence of localization and large dc conductance in random superlattices with correlated disorder
• Enhanced suppresion of localization in a continuous Random-Dimer Model
• Optical absorption in paired correlated random lattices
• Excitation decay in one-dimensional disordered systems with paired traps

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• Persistence of symmetry-protected Dirac points at the surface of the topological crystalline insulator SnTe upon impurity doping