Variational Monte Carlo Indications of d-Wave superconductivity in the two-dimensional Hubbard model

Abstract
The possibility of superconductivity in the ground state of the two-dimensional Hubbard model was investigated by means of the variational Monte Carlo method. With slight hole doping on the and lattices, a clear minimum was obtained on the curve of the total energy versus the amplitude of the d-wave gap function for large on-site Coulomb energies. Superconducting pair correlations were observed to be well developed. The-next-nearest-neighbor transfer was found to appreciably affect the minimum depth.

Keywords: two-dimensional Hubbard model, variational Monte Carlo method, superconductivity, d-wave