The Two-Dimensional Hubbard Model: Numerical Evaluation of the Properties of Projected Antiferromagnetic and Superconducting Wavefunctions
We examine the stability of generalized Gutzwiller wavefunction against Cooper pairing within the two-dimensional Hubbard model in the large U limit. The paramagnetic state is found to be stable against s-wave pairing but unstable against d-wave pairing. No (pairing energy) effect is found for the antiferromagnetic case. The calculations were done by evaluating numerically the properties of the wavefunction with a new method, which made it possible to calculate the small energy differences. We propose a pairing mechanism which is based on the nesting of the saddlepoints by the antiferromagnetic nesting vector Q = (π,π). Possible relevance for the high Tc superconductors is discussed.
KeywordsCooper Pair Small Energy Difference Anti Ferromagnetic Nest Vector Anti Ferromagnetic State
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- 2.T. M. Rice, to be published in Z. Phys. B.Google Scholar
- G. Baskaran, Z. Zou, P.W. Anderson: preprint.Google Scholar
- b) P.W. Anderson, G. Baskaran, Z. Zou, T. Hsu: preprint;Google Scholar
- Z. Zou, P.W. Anderson: preprint.Google Scholar
- 4.J. Hirsch: preprint.Google Scholar
- Y. Takahashi: preprint.Google Scholar
- 6.C. Gros, R. Joynt, T.M. Rice, Phys. Rev. B: July 1 (1987).Google Scholar
- 7.H. Yokoyama, H. Shiba: preprint.Google Scholar
- 8.C. Gros, R. Joynt, T.M. Rice: preprint.Google Scholar
- 13.P. Horsch, T. A. Kaplan, J. Phys. C 16: L1203 (1983).Google Scholar
- 14.P. Horsch, T. A. Kaplan, Bull. Am. Phys. Soc. 30:513 (1985).Google Scholar