Spin fluctuations-corrected DFT for Fe-based superconductors

ORAL

Abstract

Albeit density functional theory (DFT) is, at the moment, the most appropriate tool for treating itinerant magnetism, its mean field implementations -local spin denstity approximation (LSDA) with or without gradient corrections- underestimate the effect of non local spin fluctuations. As a result DFT fails in reproducing, at the same time, the crystal structure and the amplitude of local moment in near critical systems. In this talk I will present a simple method for correcting the magnetic properties of itinerant systems in LSDA. The method is called reduced Stoner theory (RST). I will apply this method to study the ferromagnetic-paramagnetic transition under pressure in Ni$_3$Al itinerant ferromagnet and for describing the puzzling temperature behavior of the local moment found in doped-CaFe$_2$As$_2$ pnictides.

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Authors

  • Luciano Ortenzi

    • Institute for Complex Systems (ISC), CNR, U.O.S. Sapienza, v. dei Taurini 19, 00185 Rome, Italy

  • Hlynur Gretarsson

    • Max-Planck-Institut f\"ur Festk\"orperforschung, Heisenb ergstra\'e 1, D-70569 Stuttgart, Germany

  • Shigeru Kasahara

    • Department of Physics, Kyoto University, Kyoto 606-8502, J apan
    • Kyoto University

  • Y. Matsuda

    • Department of Physics, Kyoto University, Kyoto 606-8502, J apan

  • T. Shibauchi

    • Department of Advanced Materials Science, The University o f Tokyo, Japan

  • Ken Finkelstein

    • Cornell High Energy Synchrotron Source, Cornell Universit y, Ithaca, New York 14853, USA
    • University of Illinois

  • W. Wu

    • Department of Physics, University of Toronto, 60 St. George St., Toronto, Ontario, M5S 1A7, Canada

  • S.R. Julian

    • Department of Physics, University of Toronto, 60 St. George St., Toronto, Ontario, M5S 1A7, Canada

  • Young-June Kim

    • Department of Physics, University of Toronto, 60 St. George St., Toronto, Ontario, M5S 1A7, Canada
    • University of Toronto

  • Igor Mazin

    • NRL
    • Naval Research Lab
    • code 6390, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375, USA

  • Lilia Boeri

    • Institute for Theoretical and Computational Physics, TU Gr az, Petersgasse 16, 8010 Graz, Austria