Strong coupling Hubbard model and superconductivity
Abstract
We have shown that systems open to fermion number fluctuations and described by the Hubbard model can be superconducting. This superconductivity must be accompanied by a special type of magnetic order. A unitary transformation is explicitly constructed by which the large interaction term of the Hubbard model is exactly diagonalized. Order parameters of the system related to Green functions of fermions are explicitly evaluated in the strong coupling limit. This model applied to copper-oxygen chains provides a theoretical explanation of high T c superconductivity in compounds of the type YBa2Cu3O7- x .
- Publication:
-
Czechoslovak Journal of Physics
- Pub Date:
- November 1989
- DOI:
- 10.1007/BF01605330
- Bibcode:
- 1989CzJPh..39.1302N
- Keywords:
-
- Copper Oxides;
- Fermions;
- High Temperature Superconductors;
- Mixed Oxides;
- Superconductivity;
- Barium Oxides;
- Green'S Functions;
- Hamiltonian Functions;
- Perovskites;
- Yttrium Oxides;
- Solid-State Physics