Evolution of Spin fluctuations in CaFe$_{\mathrm{2}}$As$_{\mathrm{2}}$ with Co-doping.

ORAL

Abstract

Spin fluctuations are an essential ingredient for superconductivity in Fe-based supercondcutors. In Co-doped BaFe$_{\mathrm{2}}$As$_{\mathrm{2}}$, the system goes from the antiferromagnetic (AFM) state to the superconducting (SC) state with Co doping, and the spin fluctuations also evolve from well-defined spin waves with spin gap in the AFM regime to gapless overdamped or diffused fluctuations in the SC regime. CaFe$_{\mathrm{2}}$As$_{\mathrm{2}}$ has a stronger magneto-elastic coupling than BaFe$_{\mathrm{2}}$As$_{\mathrm{2}}$ and no co-existence of SC and AFM region as observed in BaFe$_{\mathrm{2}}$As$_{\mathrm{2\thinspace }}$with Co doping. Here, we will discuss the evolution of spin fluctuations in CaFe$_{\mathrm{2}}$As$_{\mathrm{2}}$ with Co doping.

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Authors

  • A. Sapkota

    Ames Laboratory, Dept. of Physics and Astronomy, Iowa State University

  • Pinaki Das

    Ames Laboratory, Dept. of Physics and Astronomy, Iowa State University, Ames Laboratory, Iowa State University, IA, USA

  • A. E. B\"{o}hmer

    Ames Laboratory/Iowa State University, Ames Laboratory, Dept. of Physics and Astronomy, Iowa State University

  • D. L. Abernathy

    Oak Ridge National Laboratory

  • Paul Canfield

    Iowa State Univ Ames Laboratory, Ames Laboratory/ Iowa State University, Ames, IA 50011, USA, Iowa State Univ, $^A$Ames Laboratory US DOE, $^B$Department of Physics and Astronomy, $^C$Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA., Iowa State University/ Ames LabLaboratory, Ames Lab, Ames Laboratory, Dept. of Physics and Astronomy, Iowa State University, Ames Laboratory and Dept. of Phys. and Astro., Iowa State University, Ames Laboratory and Department of Physics, Iowa State University, Ames, Iowa, Iowa State Univ and Ames Laboratory, Ames Lab and Department of Physics, Iowa State University, Ames, Iowa

  • A. Kreyssig

    Ames Laboratory / Iowa State University, Ames Laboratory, Dept. of Physics and Astronomy, Iowa State University

  • R. J. McQueeney

    Ames Laboratory, Dept. of Physics and Astronomy, Iowa State University

  • A. I. Goldman

    Ames Laboratory, Dept. of Physics and Astronomy, Iowa State University