期刊論文
| 學年 | 84 |
|---|---|
| 學期 | 1 |
| 出版（發表）日期 | 1995-11-05 |
| 作品名稱 | High-temperature superconductivity in the generalized negative U Hubbard model |
| 作品名稱（其他語言） | 高溫超導在廣義負U Hubbard模型下之研究 |
| 著者 | Kocharian, A. N.; 楊棨; Yang, Chi |
| 單位 | 淡江大學物理學系 |
| 出版者 | Elsevier |
| 著錄名稱、卷期、頁數 | Materials Chemistry and Physics 42(2), pp.134-137 |
| 摘要 | A new mechanism of superconductivity in high-temperature superconducting oxides (HTSCs) with partially occupied electrons in the p and d orbitals is proposed in the generalized negative U Hubbard model, including orbital degeneracy and the strong intra-atomic attraction. Our approach allows also the introduction, in a consistent way, of the orbital mixing (hybridization) between p and d bands (orbitals). The effective anisotropic Heisenberg XYZ model consisting of pseudo-orbital variables is obtained up to second order by small parameters for arbitrary concentration of particles using unitary transformation in the strong interaction limit. The ground-state energy and the partition function are obtained in the generalized mean field approximation by introducing diagonal charge-ordering parameter η and off-diagonal superconducting order parameter Δ. The self-consistent equations are analyzed and the phase diagram in the ground state and at finite temperatures for arbitrary relations between p and d bandwidths (parameter anisotropicity g) are obtained. The competition between superconducting and charge-ordering correlations for spin and orbital variables gives rise to many different pure and intermediate phases. The proposed model elucidates the role of hybridization and orbital variables on the mechanism of HTSC. |
| 關鍵字 | Negative U Hubbard Hamiltonian;Mixed valence;Interacting fermions;Bipolaron superconductivity;Phase transitions |
| 語言 | en |
| ISSN | 0254-0584 |
| 期刊性質 | 國內 |
| 收錄於 | |
| 產學合作 | |
| 通訊作者 | |
| 審稿制度 | 否 |
| 國別 | TWN |
| 公開徵稿 | |
| 出版型式 | ,電子版 |
| 相關連結 |
機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/27677 ) |