Comparison of functional renormalization group and dynamic cluster quantum Monte Carlo results for the 2D Hubbard model

ORAL

Abstract

The Functional Renormalization Group (FRG) provides a method for determining the evolution of the 4-point scattering vertex of the Hubbard model as the temperature is lowered. Although it is usually implemented using perturbation theory, the general belief is that if the starting values of the coupling constants are chosen judiciously and the renormalization flow stopped at an appropriate point, the resulting vertex can provide unbiased information about the scattering processes that determine the low temperature properties of the system. Here, for a half-filled 2D Hubbard model, we compare a 1-loop FRG calculation with a Dynamic Cluster quantum Monte Carlo Approximation (DCA) calculation with the goal of examining this belief.

*The DCA calculations were conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. An award of computer time was provided by DOE's INCITE program.

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Authors

  • Thomas Maier

    • Oak Ridge National Laboratory
    • Computer Science and Mathematics Division and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6494, USA
    • Oak Ridge National Lab
    • Oak Ridge National Lab.

  • Carsten Honerkamp

    • Institute for Theoretical Solid State Physics, RWTH Aachen University, D-52074 Aachen, Germany

  • Daniel Rohe

    • J\"ulich Supercomputing Centre, Institute for Advanced Simulation, Forschungszentrum J\"ulich GmbH, D-52425 J\"ulich, Germany

  • Douglas Scalapino

    • Department of Physics, University of California, Santa Barbara, CA 93106-9530, USA