Incommensurate itinerant antiferromagnetic excitations and spin resonance in the FeTe$_{0.6}$Se$_{0.4}$ superconductor

ORAL

Abstract

We report on inelastic neutron scattering measurements that find incommensurate itinerant like magnetic excitations in the normal state of superconducting FeTe$_{0.6}$Se$_{0.4}$ (Tc=14K) at an incommensurate wave-vector $\mathbf{Q}_{inc}=(1/2\pm\epsilon,1/2\mp\epsilon)$ with $\epsilon$=0.09(1). In the superconducting state only the lower energy part of the spectrum shows significant changes by the formation of a gap and a magnetic resonance that follows the dispersion of the normal state excitations. We use a four band model to describe the Fermi surface topology of iron-based superconductors with the extended $s(\pm)$ symmetry and find that it qualitatively captures the salient features of these data.

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Authors

  • Z. Mao

    • Tulane University, New Orleans, LO

  • B. Qian

    • Tulane University, New Orleans, LO

  • Dimitri Argyriou

    • Helmholtz-Zentrum Berlin f\"ur Materialien und Energie, Berlin, Germany
    • Helmholtz-Zentrum Berlin fur Materialen und Energie GmbH
    • Helmholtz-Zentrum Berlin, Germany

  • A. Hiess

    • Institut Max von Laue-Paul Langevin, Grenoble, France

  • A. Akbari

    • Max-Planck-Institut f\"{u}r Physik komplexer Systeme, Dresden, Germany

  • I. Eremin

    • Max-Planck-Institut f\"{u}r Physik komplexer Systeme, Dresden, Germany

  • M.M. Korshunov

    • Max-Planck-Institut f\"{u}r Physik komplexer Systeme, Dresden, Germany

  • J. Hu

    • Tulane University, New Orleans, LO

  • Y. Qiu

    • NIST Center for Neutron Research, NIST, Gaithersburg, MD

  • C. Broholm

    • Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218 USA

  • W. Bao

    • Department of Physics, Renmin University of China, Beijing 100872, China