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Bipolaron

About: Bipolaron is a research topic. Over the lifetime, 1335 publications have been published within this topic receiving 29154 citations. The topic is also known as: bipolarons.


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Journal ArticleDOI
Hui Zhao1, Yu-Guang Chen, Xu-Ming Zhang, Z. An, Chang-Qin Wu 
TL;DR: This work uses a Su-Schrieffer-Heeger model modified to include electron-electron interactions via a Hubbard Hamiltonian, a Brazovskii-Kirova symmetry-breaking term, and an external electric field and shows that the velocity of the bipolaron increases first and then decreases with the increasing of the on-site Coulomb interaction.
Abstract: By employing an adaptive time-dependent density-matrix-renormalization-group method, we investigate the dynamics of a charged bipolaron in the presence of both electron-phonon and electron-electron interactions. We use a Su–Schrieffer–Heeger model modified to include electron-electron interactions via a Hubbard Hamiltonian, a Brazovskii–Kirova symmetry-breaking term, and an external electric field. Our results show that the velocity of the bipolaron increases first and then decreases with the increasing of the on-site Coulomb interaction, U. Furthermore, the dependence of the bipolaron velocity, bipolaron effective mass, and bipolaron stability on the lattice structures is discussed.

17 citations

Journal ArticleDOI
TL;DR: In this paper, photo-induced electronic and vibrational absorption of polydiacetylene (10H) in the infrared (400-4000 cm-1) was found to be consistent with photo-generation of bipolarons.
Abstract: Photo-induced electronic and vibrational absorption of polydiacetylene (10H) in the infrared (400-4000 cm-1) is found to be consistent with photo-generation of bipolarons Overlap of electronic and vibrational transitions occurs due to strong electron correlation effects which reduce the electronic transition energies Electron-phonon interaction produces anti-resonances in the bipolaron electronic absorption

17 citations

Journal ArticleDOI
TL;DR: In this article, structural and electronic transitions in poly(phenylenesulfide phenyleneamine) (PPSA) upon electrochemical doping have been investigated, and the results indicate that polarons are the predominant charge defects at low doping levels, yielding an electronically and mechanically stable material.
Abstract: Structural and electronic transitions in poly(phenylenesulfide phenyleneamine) (PPSA) upon electrochemical doping have been investigated. The results indicate that polarons are the predominant charge defects at low doping levels, yielding an electronically and mechanically stable material. The electrochemical doping at high potentials induces a transition of the polarons to a bipolaron state. Due to the heterogeneous nature of the polymer chain and different oxidation potentials associated with aniline and phenylene sulfide units, the formation of polaron and bipolaron is distinguished as two separated steps. The dopant perchlorate ion exists in the polymer matrix, not only as charge neutralizer but also as a ligand that is simultaneously Coulombically bound to the positively charged S or N sites on one polymer chain and hydrogen bonded to the N−H group on the neighboring chain. The formation of such perchlorate anion centered Coulombic/hydrogen-bonded complexes has a major impact on the electrochemical a...

17 citations

Journal ArticleDOI
TL;DR: In this paper, the spin-lattice relaxation rate (T 1 −1 ) was measured as a function of NMR frequency over a wide range (4-300MHz). And the singular dependence upon frequency characteristic of the low-dimensional (one and two-dimensional) diffusive motion of electrons was found.

16 citations

Journal ArticleDOI
TL;DR: In this article, it is suggested that all the carriers (oxygen 2p holes) form bipolarons, and that they are responsible for the current above and below T c. The model breaks down for concentrations (x) of carriers so great that Tc decreases with x, for which overlap between the polarons may lead to BCS behaviour with breakup of the bosons above Tc, but not necessarily phonon-induced pairing.
Abstract: Starting from the model of spin-dielectric polarons proposed by the author and others, it is suggested that all the carriers (oxygen 2p holes) form bipolarons, and that they are responsible for the current above and below T c. A comparison is made with superfluid 4He in which only 10% of the helium atoms are believed to condense into the zero-momentum state. A similar assumption for the superconductors can account for the small values of the change of entropy through the transition. The model breaks down for concentrations (x) of carriers so great that Tc decreases with x, for which overlap between the polarons may lead to BCS behaviour with breakup of the bosons above Tc , but not necessarily phonon-induced pairing. It is suggested also that the model is compatible with observations of a Fermi surface.

16 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202316
202229
202127
202023
201920
201833