|
| | | | |
| | | |
| Stat |
Members: 3665
Articles: 2'599'751
Articles rated: 2609
20 January 2025 |
|
| | | | |
|
Article overview
| |
|
|
Correlaction Effects on the Band Gap of Conducting Polymers | | C.Q.Wu
; | | Date: |
23 Oct 1992 | | Abstract: | By applying the projection technique to the computation of excitation energies, we study the correlation effects on the band gap of conducting polymers. In the presence of an additional electron or hole, the correlation induces a polarization cloud around the addi- tional particle, which forms a polaron. For the excitation energy of a polaron,there is a competition between a {it loss} of the correla- tion energy in the ground state and a {it gain} of polarization energy. For the Hubbard interaction, the {it loss} of correlation energy is dominant and correlations increase the band gap.However,for long-range interactions, the {it gain} of polarization energy is dominant and correlations decrease the band gap. Screening the long- range interaction suppresses the {it gain}of the polarization energy so that correlations again increase the band gap.A small dimerization is always favorable to the correlation effects. For {it trans}-poly- acetylene, we obtain the on-site repulsion $U=4.4$eV and the nearest- neighbor interaction $V=0.8$ eV. The screening of $pi$ electrons due to the polarizability of $sigma$ electrons is quite strong. ** to be published in Phys. Rev. B | | Source: | arXiv, cond-mat/9210022 | | Services: | Forum | Review | PDF | Favorites | |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
|
| |
|
|
|
REGISTER