Finite-temperature phase diagram of the Hubbard model
Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
2 Feza Gürsey Research Center for Basic Sciences, Çengelköy, Istanbul 81220, Turkey
3 Department of Physics, Istanbul Technical University, Maslak, Istanbul 80626, Turkey
Published online: 15 September 2000
The finite-temperature phase diagram of the Hubbard model in d=3 is obtained from renormalization-group analysis. It exhibits, around half filling, an antiferromagnetic phase and, between 30% -40% electron or hole doping from half filling, a new phase in which the electron hopping strength t asymptotically becomes infinite under repeated rescalings. Next to the phase, a first-order phase boundary with very narrow phase separation (less than 2% jump in electron density) occurs. At temperatures above the phase, an incommensurate spin modulation phase is indicated. In d=2, we find that the Hubbard model has no phase transition at finite temperature.
PACS: 71.10.Fd – Lattice fermion models (Hubbard model, etc.) / 74.25.Dw – Superconductivity phase diagrams / 05.30.Fk – Fermion systems and electron gas
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000