Journal ArticleDOI
Electronic States in Doped trans-Polyacetylene -Coherent Potential Approximation and Compensated Doping-
TLDR
In this article, the authors used an extended Takayama-Lin-Liu-Maki (TLM) model to study the order effects in doped trans-polyacetylene.Abstract:
Disorder effects in doped trans -polyacetylene are studied, using an extended Takayama-Lin-Liu-Maki (TLM) model. Bond- and site-type impurity models are analyzed when the doping is compensated. Electronic states are calculated by the self-consistent Born approximation (SCBA) and also by the coherent potential approximation (CPA). Results do not depend on the type of the impurity. We find that peaks in the electronic density of states become steeper and the energy gap is wider in the CPA than in the SCBA, while change in the order parameter is small. Two critical concentrations, where the gap and the order parameter vanish, come close each other. A phase diagram is given for the electronic structures in the CPA. For the site-type impurities, two impurity bands are found in association with the two signs of impurities. For the bond-type impurities, the total energy recovers the symmetry property for the order parameter.read more
Citations
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Journal ArticleDOI
Inter-impurity interaction and structure of a trapped bipolaron in doped conjugated polymers
TL;DR: In this paper, the Coulomb interactions in the chain were treated by the Hartree-Fock approximation, and the effects of interimpurity interaction were studied by the extended Peierls-Hubbard model.
Journal ArticleDOI
Metal-insulator transition in doped conducting polymers: Disappearance of electronic gap with persisting bond alternation
Kikuo Harigaya,Akira Terai +1 more
TL;DR: In this paper, the authors investigated the electronic states of polyacetylene, using the SSH model with site-type impurities randomly distributed, and determined the lattice configuration and electronic wave functions self-consistently with full lattice relaxation.
Journal ArticleDOI
An Anderson impurity in conjugated polymers. I. A new localized state in the electronic gap for the impurity with U=0
TL;DR: In this paper, Anderson impurity in conjugated polymers is formulated in order to investigate the effects of a dopant, a carbonyl (>C=O) defect or an atomic side group.
Journal ArticleDOI
Electronic states in doped trans-polyacetylene: numerical simulation of half-filled systems
TL;DR: In this paper, the SSH model with a random distribution of impurities was used to simulate a polyacetylene system composed of one hundred (CH) units, electrons of the same number, and impurities of concentration up to eight percent.
Book ChapterDOI
Doping and Disorder in Conducting Polymers
TL;DR: In this paper, a review of experiments which have studied the structure of doped polyacetylene with the help of X-ray diffraction is presented, with particular emphasis on the relation between polymer chains and dopant columns along the chain direction, and the experiments have not ruled out the possibility that electrons in the polymer chains may be in more or less disordered circumstances.
References
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Journal ArticleDOI
Solitons in conducting polymers
TL;DR: In this article, the authors review the theoretical models that have been developed to describe the physics of polyacetylene and related conducting polymers and summarize the relevant experimental results obtained for these materials.
Journal ArticleDOI
Soliton excitations in polyacetylene
TL;DR: A theoretical analysis of the excitation spectrum of long-chain polyenes is presented in this paper, where one electronic state is localized at the gap center for each soliton or antisoliton present and the soliton's energy of formation, length, mass, activation energy for motion, and electronic properties are calculated.
Journal ArticleDOI
Continuum model for solitons in polyacetylene
TL;DR: In this article, a variational solution with the displacement order parameter was analyzed for solons in a one-dimensional charge-density-wave system with half-filled electron bands.
Journal ArticleDOI
The energy spectrum of disordered systems
TL;DR: In this article, a detailed report of the theoretical work carried out by the author during recent years on problems connected with the energy spectrum of a disordered solid is given, with indications of applications to particular problems, such as the lattice vibrational spectrum of an imperfect crystal and the electronic levels associated with impurity atoms.
Journal ArticleDOI
Green's Functions for a Particle in a One-Dimensional Random Potential
TL;DR: In this article, the spectral density of a particle in a one-dimensional random potential, where the potential at each point is statistically independent of the potential in all other points, is calculated by solving the equation of motion for the probability distribution.