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