We describe studies of the effects of defects on Hubbard models of high T c superconductors. We first present numerical mean field calculations on the t-J model in which disorder due to point defects in treated explicitly. Secondly, we describe variational Monte Carlo calculations at zero temperature in which the full effects of the Gutzwiller projection are included in a calculation of the variational BCS ground state including randomly distributed point defects. Finally we discuss possible microscopic mechanisms by which point defects could enhance pairing in the BCS state.
- Hubbard models
- Point defects