1997/01/31 by Elisa Ercolessi, P. Pieri, Pierbiagio Pieri +2
Physics and Astronomy · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Theoretical and Computational Physics #cond-mat.str-el
paper · pdf · doi:10.1016/s0375-9601(97)00464-7
published as Phys. Lett. A 233, 451 (1997) · 10 pages, LaTex, 3 Postscript figures
arxiv created 1997/06/09 · openalex publication_date 1997/09/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We study the t-J model with the inclusion of the so called three-site term which comes out from the t/U --> 0 expansion of the Hubbard model. We find that this singlet pair hopping term has no qualitative effect on the structure of the pure mean field phase diagram for nonmagnetic states. In accordance with experimental data on high-Tc materials and some numerical studies, we also find wide regions of phase coexistence whenever the coupling J is greater than a critical value Jc. We show that Jc varies linearly with the temperature T, going to zero at T=0.