Next Materials Science Home

Superconductors are materials which below a so-called critical temperature have a vanishing resistance and a tendency to expel magnetic fields. Until 1985, the maximum critical temperature at which materials became superconducting was about 20 K. With the discovery of so-called high-T_c superconductors, this maximum temperature has been raised to about 140 K.

The Hubbard model is one of the most simple models for strongly correlated many-electron systems and has been studied extensively in the context of high-T_c materials. While the model can only be solved exactly in one dimension, several approximate solutions exist. Among those are variational approaches such as BCS-type calculations, variants of the Gutzwiller wave function, or the unrestricted Hartree-Fock method. We generalize a variational approach by Barentzen to the attractive and extended Hubbard model to arbitrary band filling in one, two, and three dimensions.

To cite this page:
Materials Science: Hubbard Model for High-T_c Materials
<http://www.physics.ohio-state.edu/~aulbur/hub/hub.html>