Theoretical aspects of charge correlations in θ-(BEDT-TTF)2X
A review is given on the theoretical studies of charge correlations in θ-(BEDT-TTF)2X. Various studies show that within a purely electronic model on the θ-type lattice with on-site U and nearest neighbor Vp and Vc interactions, the diagonal stripe, c-axis three-fold, and the vertical stripe charge c...
| Main Author: | |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Taylor & Francis Group
2009-01-01
|
| Series: | Science and Technology of Advanced Materials |
| Subjects: | |
| Online Access: | http://www.iop.org/EJ/abstract/1468-6996/10/2/024312 |
| _version_ | 1818265073582342144 |
|---|---|
| author | Kazuhiko Kuroki |
| author_facet | Kazuhiko Kuroki |
| author_sort | Kazuhiko Kuroki |
| collection | DOAJ |
| description | A review is given on the theoretical studies of charge correlations in θ-(BEDT-TTF)2X. Various studies show that within a purely electronic model on the θ-type lattice with on-site U and nearest neighbor Vp and Vc interactions, the diagonal stripe, c-axis three-fold, and the vertical stripe charge correlations are favored in the regime Vp<Vc, Vp~Vc, and Vp>Vc, respectively. In the realistic parameter regime of Vp~Vc, there is competition between the c-axis three fold state and diagonal stripe state. Since these are different from the experimentally observed a-axis three fold and the horizontal stripe charge correlations, additional effects have to be included in order to understand the experiments. The electron–lattice coupling, which tends to distort the lattice into the θd-type, is found to favor the horizontal stripe state, suggesting that the occurrence of this stripe ordering in the actual materials may not be of purely electronic origin. On the other hand, distant electron–electron interactions have to be considered in order to understand the a-axis three fold correlation, whose wave vector is close to the nesting vector of the Fermi surface. These studies seem to suggest that the minimal model to understand the charge correlation in θ-(BEDT-TTF)2X may be more complicated than expected. Future problems regarding the competition between different types of charge correlations are discussed. |
| first_indexed | 2024-12-12T19:45:01Z |
| format | Article |
| id | doaj.art-5686fb0ca2c64f70b217e35a439b8f98 |
| institution | Directory Open Access Journal |
| issn | 1468-6996 1878-5514 |
| language | English |
| last_indexed | 2024-12-12T19:45:01Z |
| publishDate | 2009-01-01 |
| publisher | Taylor & Francis Group |
| record_format | Article |
| series | Science and Technology of Advanced Materials |
| spelling | doaj.art-5686fb0ca2c64f70b217e35a439b8f982022-12-22T00:14:06ZengTaylor & Francis GroupScience and Technology of Advanced Materials1468-69961878-55142009-01-01102024312Theoretical aspects of charge correlations in θ-(BEDT-TTF)2XKazuhiko KurokiA review is given on the theoretical studies of charge correlations in θ-(BEDT-TTF)2X. Various studies show that within a purely electronic model on the θ-type lattice with on-site U and nearest neighbor Vp and Vc interactions, the diagonal stripe, c-axis three-fold, and the vertical stripe charge correlations are favored in the regime Vp<Vc, Vp~Vc, and Vp>Vc, respectively. In the realistic parameter regime of Vp~Vc, there is competition between the c-axis three fold state and diagonal stripe state. Since these are different from the experimentally observed a-axis three fold and the horizontal stripe charge correlations, additional effects have to be included in order to understand the experiments. The electron–lattice coupling, which tends to distort the lattice into the θd-type, is found to favor the horizontal stripe state, suggesting that the occurrence of this stripe ordering in the actual materials may not be of purely electronic origin. On the other hand, distant electron–electron interactions have to be considered in order to understand the a-axis three fold correlation, whose wave vector is close to the nesting vector of the Fermi surface. These studies seem to suggest that the minimal model to understand the charge correlation in θ-(BEDT-TTF)2X may be more complicated than expected. Future problems regarding the competition between different types of charge correlations are discussed.http://www.iop.org/EJ/abstract/1468-6996/10/2/024312θ-(BEDT-TTF)2Xcharge orderingelectron–electron interactionapproximationFermi surface |
| spellingShingle | Kazuhiko Kuroki Theoretical aspects of charge correlations in θ-(BEDT-TTF)2X Science and Technology of Advanced Materials θ-(BEDT-TTF)2X charge ordering electron–electron interaction approximation Fermi surface |
| title | Theoretical aspects of charge correlations in θ-(BEDT-TTF)2X |
| title_full | Theoretical aspects of charge correlations in θ-(BEDT-TTF)2X |
| title_fullStr | Theoretical aspects of charge correlations in θ-(BEDT-TTF)2X |
| title_full_unstemmed | Theoretical aspects of charge correlations in θ-(BEDT-TTF)2X |
| title_short | Theoretical aspects of charge correlations in θ-(BEDT-TTF)2X |
| title_sort | theoretical aspects of charge correlations in θ bedt ttf 2x |
| topic | θ-(BEDT-TTF)2X charge ordering electron–electron interaction approximation Fermi surface |
| url | http://www.iop.org/EJ/abstract/1468-6996/10/2/024312 |
| work_keys_str_mv | AT kazuhikokuroki theoreticalaspectsofchargecorrelationsinthbedtttf2x |