Abstract
We present a controlled perturbative approach to the low-temperature phase diagram of highly inhomogeneous Hubbard models in the limit of small coupling, , between clusters. We apply this to the dimerized and checkerboard models. The dimerized model is found to behave like a doped semiconductor, with a Fermi-liquid groundstate with parameters (e.g., the effective mass) which are smooth functions of the Hubbard interaction, . By contrast, the checkerboard model has a Fermi liquid phase at large , a -wave superconducting state with a full gap for , and a narrow strip of an intermediate -wave superconducting phase with gapless “nodal” quasiparticles for .
- Received 20 December 2005
DOI:https://doi.org/10.1103/PhysRevB.73.214510
©2006 American Physical Society