R.J. Gambino, N.R. Stemple, et al.
Journal of Physics and Chemistry of Solids
The appropriate infinite-wavelength qi→0 and zero-frequency ω→0 limits of the paramagnetic current-current correlation function provide criteria for determining whether a system is insulating, metallic, or superconducting. Here we discuss these criteria for lattice models and present Monte Carlo data for the two-dimensional positive- and negative-U Hubbard models that imply that the ground state of the half-filled positive-U Hubbard model is an insulator, the doped state is a metal, and the negative-U Hubbard model is a superconductor. © 1993 The American Physical Society.
R.J. Gambino, N.R. Stemple, et al.
Journal of Physics and Chemistry of Solids
O.F. Schirmer, K.W. Blazey, et al.
Physical Review B
C.M. Brown, L. Cristofolini, et al.
Chemistry of Materials
A. Gupta, R. Gross, et al.
SPIE Advances in Semiconductors and Superconductors 1990