Exact diagonalization study of Mott transition in the Hubbard model on an anisotropic triangular lattice

Takashi Koretsune, Yukitoshi Motome, Akira Furusaki

Research output: Contribution to journalArticlepeer-review

51 Citations (Scopus)

Abstract

We study Mott transition in the two-dimensional Hubbard model on an anisotropic triangular lattice. We use the Lanczos exact diagonalization of finite-size clusters up to eighteen sites, and calculate Drude weight, charge gap, double occupancy and spin structure factor. We average these physical quantities over twisted boundary conditions in order to reduce finite-size effects. We find a signature of the Mott transition in the dependence of the Drude weight and/or charge gap on the system size. We also examine the possibility of antiferromagnetic order from the spin structure factor. Combining these information, we propose a ground-state phase diagram which has a nonmagnetic insulating phase between a metallic phase and an insulating phase with antiferromagnetic order. Finally, we compare our results with those reported in the previous theoretical studies, and discuss the possibility of an unconventional insulating state.

Original languageEnglish
Article number074719
Journaljournal of the physical society of japan
Volume76
Issue number7
DOIs
Publication statusPublished - 2007 Jul
Externally publishedYes

Keywords

  • Averaging over twisted boundary conditions
  • Drude weight
  • Geometrical frustration
  • Hubbard model
  • Lanczos exact diagonalization
  • Mott transition

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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