Coexistence between superconductivity and magnetism in the iron pnictides

ORAL

Abstract

In this work, we present a theory to analyze the coexistence between the antiferromagnetic and the superconducting phases in the iron arsenides. Particularly, we focus on how distinct regimes of competition between these two phases are related to different symmetries of the Cooper pair wave-function. Using a mean-field microscopic model where superconductivity and itinerant antiferromagnetism are caused by electrons sharing the same bands, we show that while the so-called $s^{++}$ state is generally incompatible to the antiferromagnetic phase, the unconventional $s^{+-}$ state can coexist with magnetism depending on the Fermi surface topology. Neutron diffraction data on $\mathrm{Ba(Fe_{1-x}Co_{x})_{2}As_{2}}$ supporting these conclusions are also presented.

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Authors

  • Rafael Fernandes

    Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011

  • Michael Turner

    Illinois Institute of Technology, Bettendorf High School, Bettendorf, IA, Mississippi Bend Area Education Agency, Bettendorf, IA, Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA, Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA, Max-Planck-Institut fuer Mikrostrukturphysik, Halle, Germany, CNRS, Universite Lyon I, France, Freie Universitaet Berlin, Germany, University of Jyvaskila, Finaland, Iowa State University/Ames Laboratory, Materials Science Division, Argonne National Laboratory and Department of Chemistry, Northwestern University, Materials Science Division, Argonne National Laboratory, Advanced Photon Source, Argonne National Laboratory, Ames Laboratory and Iowa State University, Indiana University, Illinois State University, University of Iowa, Louisiana State University, University of Warwick, Rutherford Appleton Laboratory, Coe College, University of Northern Iowa, Iowa State University and Ames Laboratory, University of Illinois, Ames Laboratory, University of Florida, Tulane University, The Department of Physics and The James Franck Institute, The University of Chicago, J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, Department of Physics, Augustana College, Sioux Falls, SD 57197, Intense Laser Physics Theory Unit, Illinois State University, Argonne National Laboratory, Dr, Drake University, Physics Department, Ocean University of China, Qingdao, Physics Department, Southern Illinois University Carbondale, Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, USA, Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA, NEST-CNR-INFM and Scuola Normale Superiore, I-56126 Pisa, Italy, University of New Hampshire Department of Physics, University of Chicago