Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Bulletin of the American Physical Society

Quantum Monte Carlo Study of ``Fictive Impurity'' to Half-Filled Hubbard Model

Andreas Fuhrmann, Satoshi Okamoto, Andrew J. Millis

Published Mar 24, 2005• 0 citations
OpenAlex

Related papers

Monte Carlo simulation of nearly half-filled Hubbard model in the ground state

Nobuo Furukawa, Masatoshi Imada

Physica C Superconductivity•Dec 1, 1991•3 citations

On the charge-excitation gap of the 2D half-filled Hubbard model: A quantum Monte Carlo study

Feng Chen, He-Ping Ying, Tiefeng Xu +1 more

Physics Letters A•Jun 1, 1994•2 citations

Fictive-impurity approach to dynamical mean-field theory: A strong-coupling investigation

A. Fuhrmann, Satoshi Okamoto, H. Monien +1 more

Quantum Monte Carlo and semiclassical methods are used to solve two- and four-site cluster dynamical mean-field approximations to the square-lattice Hubbard model at half filling and strong coupling. The dyanmical cluster approximation, cluster dynamical mean-field theory, and fictive-impurity approaches are compared. The energy, spin correlation function, phase boundary, and electron spectral function are computed and compared to available exact results. The comparision permits a quantitative assessment of the ability of the different methods to capture the effects of intersite spin correlations. Two real-space methods and one momentum-space representation are investigated. One of the two real-space methods is found to be significantly worse: in it, convergence to the correct results is found to be slow and, for the spectral function, nonuniform in frequency, with unphysical midgap states appearing. Analytical arguments are presented showing that the discrepancy arises because the method does not respect the pole structure of the self-energy of the insulator. Of the other two methods, the momentum-space representation is found to provide the better approximation to the intersite terms in the energy but neither approximation is particularly acccurate and the convergence of the momentum-space method is not uniform. A few remarks on numerical methods are made.

arXiv:cond-mat/0605133•Physical Review B•May 21, 2007•20 citations

Quantum Monte Carlo study of the Hubbard model

Wolfgang von der Linden, I. Morgenstern, Hans A. De Raedt

•Jan 1, 1990•0 citations

Quantum Monte Carlo Simulation of One-Dimensional Periodic Anderson Model

Tetsuro Saso, Yutaka Seino

Quantum Monte Carlo[MC] calculation of one-dimensional periodic Anderson model without orbital degeneracy is performed by use of the path-integral formulation. Local f moment coincides well with the recent MC calculation for single impurity by Hirsch and Fye above the temperature at which antiferromagnetic correlation starts to grow, and decreases faster than those for single impurity and coupled two impurities below that temperature. Overall features, including susceptibilities, resemble one-dimensional Hubbard model with half-filled band.

Journal of the Physical Society of Japan•Nov 15, 1986•21 citations

ORDERED STATES IN THE DISORDERED HUBBARD MODEL

P. J. H. Denteneer, M. Ulmke, Richard T. Scalettar +1 more

The Hubbard model is studied in which disorder is introduced by putting the on-site interaction to zero on a fraction f of (impurity) sites of a square lattice. Using Quantum Monte Carlo methods and Dynamical Mean–Field Theory we find that antiferromagnetic long–range order is initially enhanced at half–filling and stabilized off half-filling by the disorder. The Mott-Hubbard charge gap of the pure system is broken up in two pieces by the disorder: one incompressible state remains at average density n = 1 and another can be seen slightly below n = 1 + f. Qualitative explanations are provided.

•Jan 1, 1998•3 citations
Quantum Monte Carlo and semiclassical methods are used to solve two- and four-site cluster dynamical mean-field approximations to the square-lattice Hubbard model at half filling and strong coupling. The dyanmical cluster approximation, cluster dynamical mean-field theory, and fictive-impurity approaches are compared. The energy, spin correlation function, phase boundary, and electron spectral function are computed and compared to available exact results. The comparision permits a quantitative assessment of the ability of the different methods to capture the effects of intersite spin correlations. Two real-space methods and one momentum-space representation are investigated. One of the two real-space methods is found to be significantly worse: in it, convergence to the correct results is found to be slow and, for the spectral function, nonuniform in frequency, with unphysical midgap states appearing. Analytical arguments are presented showing that the discrepancy arises because the method does not respect the pole structure of the self-energy of the insulator. Of the other two methods, the momentum-space representation is found to provide the better approximation to the intersite terms in the energy but neither approximation is particularly acccurate and the convergence of the momentum-space method is not uniform. A few remarks on numerical methods are made.
Quantum Monte Carlo[MC] calculation of one-dimensional periodic Anderson model without orbital degeneracy is performed by use of the path-integral formulation. Local f moment coincides well with the recent MC calculation for single impurity by Hirsch and Fye above the temperature at which antiferromagnetic correlation starts to grow, and decreases faster than those for single impurity and coupled two impurities below that temperature. Overall features, including susceptibilities, resemble one-dimensional Hubbard model with half-filled band.
The Hubbard model is studied in which disorder is introduced by putting the on-site interaction to zero on a fraction f of (impurity) sites of a square lattice. Using Quantum Monte Carlo methods and Dynamical Mean–Field Theory we find that antiferromagnetic long–range order is initially enhanced at half–filling and stabilized off half-filling by the disorder. The Mott-Hubbard charge gap of the pure system is broken up in two pieces by the disorder: one incompressible state remains at average density n = 1 and another can be seen slightly below n = 1 + f. Qualitative explanations are provided.