RT Journal Article
T1 Three-dimensional effects on extended states in disordered models of polymers
A1 DomÃnguez-Adame, Francisco
A1 Diez, Enrique
A1 SÃ¡nchez, Angel
AB We study electronic transport properties of disordered polymers in a quasi-one-dimensional model with fully three-dimensional interaction potentials. We consider such quasi-one-dimensionallatticesin the presence of both uncorrelated and short-range correlated impurities. In our procedure, theactual physical potential acting upon the electrons is replaced by a set of nonlocal separable potentials,leading to a Schrodinger equation that is exactly solvable in the momentum representation. Bychoosing an appropriate potential with the same spectral structure as the physical one, we obtaina discrete set of algebraic equations that can be mapped onto a tight-binding-like equation. Wethen 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 unityfor 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 trulyextended in the thermodynamic limit. These results are obtained with parameters taken from actualphysical systems such as polyacetylene, and thus reinforce the possibility of verifying experimentally theoretical predictions about the absence of localization in quasi-one-dimensional disordered systems.
PB American Physical Society
SN 1098-0121 (print version)
SN 1550-235X (online version)
YR 1995
FD 1995-04-01
LK https://hdl.handle.net/10016/15230
UL https://hdl.handle.net/10016/15230
LA eng
NO Work at Madrid is supported by UCM through Project No. PR161/93-4811. Work at Leganes is supported by the DGICyT (Spain) through Project No. PB92-0248, and by the European Union Human Capital and Mobility Programme through Contract No. ERBCHRXCT930413.
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RD 15 jun. 2024