Electron-lattice coupling and partial nesting as the origin of Fermi arcs in manganites

ORAL

Abstract

We present a detailed Monte Carlo study of the one-particle spectral function using a double-exchange model for layered manganites, incorporating lattice distortions. Our results contribute to clarifying the physical origin of the Fermi arcs observed in ARPES experiments on bilayered manganites.\footnote{Manella {\it el al.} Nature 438, 474 (2005)} In a range of parameters where no broken symmetry phase exists, the nearly-nested Fermi surface favors particular correlations between the Jahn-Teller distortions. Due to these correlations, the spectral weight is surpresed near the Brillouin zone edge, while a quasiparticle peak survives in the zone diagonal. This regime manifests as a pseudogap in the density of states, and produces a Fermi-arc like Fermi surface.\footnote{Salafranca {\it el al.} Phys. Rev. B 80, 155133 (2009)} We also discuss the stability of the pseudogap varying the temperature and the electron-lattice coupling strength for different hole dopings.

*Suported by NSF, Grant No. DMR-0706020 and the Div. of Mat. Science and Engineering, U.S. DOE under contract with UT-Batelle, LLC.

Authors

  • Juan Salafranca

    • University of Tennessee and ORNL
  • Gonzalo Alvarez

    • Oak Ridge National Lab
    • ORNL
    • Oak Ridge National Laboratory
  • Elbio Dagotto

    • Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
    • University of Tennessee, Knoxville and Oak Ridge National Lab
    • University of Tennessee and ORNL
    • University of Tennessee, Oak Ridge National Laboratory