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oai:nagoya.repo.nii.ac.jp:00009475
2023-01-16T03:55:06Z
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Predominant magnetic states in the Hubbard model on anisotropic triangular lattices
Watanabe, T.
Yokoyama, H.
Tanaka, Y.
Inoue, J.
open access
Copyright: American Physical Society, All rights reserved.
antiferromagnetic materials
d-wave superconductivity
Hubbard model
magnetic domains
metal-insulator transition
Monte Carlo methods
organic superconductors
renormalisation
superconducting energy gap
superconducting transitions
variational techniques
By using an optimization variational Monte Carlo method, we study the half-filled-band Hubbard model on anisotropic triangular lattices, as a continuation of the preceding study [T. Watanabe, H. Yokoyama, Y. Tanaka, and J. Inoue, J. Phys. Soc. Jpn. 75, 074707 (2006)]. We introduce two new trial states: (i) A coexisting state of Ψ^co_Q -antiferromagnetic (AF) and a d-wave singlet gaps, in which we allow for a band renormalization effect, and (ii) a state with an AF order of 120° spin structure. In both states, a first-order metal-to-insulator transition occurs at smaller U/ t than that of the pure d-wave state. In insulating regimes, magnetic orders always exist; an ordinary (π,π)-AF order survives up to t'/t~0.9 (U/ t=12), and a 120°-AF order becomes dominant for t'/ t. The regimes of the robust superconductor and of the nonmagnetic insulator the preceding study proposed give way to these magnetic domains.
American Physical Society
2008-06
eng
journal article
VoR
http://hdl.handle.net/2237/11256
https://nagoya.repo.nii.ac.jp/records/9475
https://doi.org/10.1103/PhysRevB.77.214505
1098-0121
PHYSICAL REVIEW B
77
21
214505
214505
https://nagoya.repo.nii.ac.jp/record/9475/files/PhysRevB_77_214505.pdf
application/pdf
670.5 kB
2018-02-20