Extended Correlation in Strongly Correlated Systems, Beyond Dynamical Cluster Approximation

ORAL

Abstract

We present a new multi-scale approach for strongly correlated systems that combines the Dynamical Cluster Approximation and the recently introduced dual-fermion formalism. This approach employs an exact mapping from a real lattice to a DCA cluster of linear size $L_c$ embedded in a dual fermion lattice. The short-length-scale physics is addressed by DCA cluster calculations, while the longer-length-scale physics is addressed diagrammatically using dual fermions. The bare and dressed dual fermionic Green functions scale as ${\cal{O}}(1/L_c)$, so perturbation theory on the dual lattice converges very quickly. E.g., the dual Fermion self-energy calculated with simple second order perturbation theory is of order ${\cal{O}}(1/L_c^3)$, with third order and three-body corrections down by an additional factor of ${\cal{O}}(1/L_c)$.

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Authors

  • Herbert Fotso

    • Georgetown University
    • Department of Physics, Georgetown University

  • Shuxiang Yang

    • Louisiana State University
    • Department of Physics and Astronomy, Louisiana State University
    • Department of Physics \& Astronomy, Louisiana State University

  • Hartmut Hafermann

    • Centre de Physique Theorique, Ecole Polytechnique
    • Centre de Physique Theorique, Ecole Polytechnique, CNRS, France

  • Ka-Ming Tam

    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
    • Louisiana State University (LSU)
    • Louisiana State University
    • Department of Physics and Astronomy, Louisiana State University
    • Department of Physics \& Astronomy, Louisiana State University

  • Juana Moreno

    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA
    • Louisiana State University
    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA
    • Department of Physics and Astronomy, Louisiana State University
    • Department of Physics \& Astronomy, Louisiana State University

  • Thomas Pruschke

    • Georg-August-Universit\"at G\"ottingen
    • Department of Physics, University of Goettingen

  • Mark Jarrell

    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA
    • Louisiana State University
    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA
    • Louisiana State University (LSU)
    • Department of Physics and Astronomy, Louisiana State University
    • Department of Physics \& Astronomy, Louisiana State University