- Tytuł:
- Ferromagnetic Ground State of Two-Band Hubbard Model with One Electron per Site
- Autorzy:
-
Schulenburg, J.
Richter, J. - Powiązania:
- https://bibliotekanauki.pl/articles/1955522.pdf
- Data publikacji:
- 1997-02
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
75.40.Mg
75.30.Et
75.50.Dd
75.10.Lp - Opis:
- We study the multiband mechanism to favour a ferromagnetic insulating ground state within a two-band Hubbard model. Besides perturbation theory we use exact diagonalization studies to examine the ground state of chains and 2D-lattices. According to second order perturbation theory the exact diagonalization yields a fully polarized ferromagnetic ground state, if the hopping between two ground state orbitals of neighbouring atoms t$\text{}_{gg}$ is small and the hopping between a ground state orbital and an excited orbital t$\text{}_{ge}$ dominates. However, in contrast to the suggestion from the second order perturbation theory this ferromagnetic state is stable only for very small hopping integrals U≫ t$\text{}_{ge}$>t$\text{}_{gg}$. For larger t $\text{}_{ge}$ quantum interference effects lead to complex magnetic structures.
- Źródło:
-
Acta Physica Polonica A; 1997, 91, 2; 367-370
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł