Quasiparticle Interference Imaging of the Nematic Electronic Structure in the Parent State of Iron-Based Superconductor Ca(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$

ORAL

Abstract

Spectroscopic imaging STM is used to study the electronic structure of Ca(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$ (x=0.03) in the parent state from which the superconductivity emerges. The electronic structure in k-space determined by Fourier transform of real-space conductance images reveals the unidirectional dispersion along b-axis with additional apparent band folding along a-axis. These C2 symmetric quasiparticle interference modulations rotate with orthorhombic twin boundaries. These observations indicate a more complicated electronic nematicity than originally expected in the ferropnictide parent state.

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Authors

  • Tien-Ming Chuang

    • Cornell University, National High Magnetic Field Lab

  • Milan Allan

    • Cornell University, University of St. Andrews

  • Jinho Lee

    • Brookhaven National Laboratory
    • Cornell University, Brookhaven National Lab

  • Yang Xie

    • Cornell University

  • N. Ni

    • Ames Laboratory and Iowa State University, IA, USA
    • Ames Laboratory / Iowa State University
    • Ames Laboratory
    • Dept of Physics/Ames Laboratory, Iowa State University
    • Department of Physics and Astronomy, Iowa State University

  • S.L. Bud'ko

    • Ames Laboratory and Iowa State University, IA, USA
    • Ames Laboratory / Iowa State University
    • Ames Laboratory
    • Ames Laboratory/Iowa State University
    • Dept of Physics/Ames Laboratory, Iowa State University
    • Ames Laboratory and Department of Physics and Astronomy, Iowa State University

  • Greg Boebinger

    • National High Magnetic Field Laboratory
    • NHMFL/FSU

  • P.C. Canfield

    • Ames Laboratory and Iowa State University, IA, USA
    • Ames Laboratory / Iowa State University
    • Ames Laboratory
    • Dept of Physics/Ames Laboratory, Iowa State University
    • Ames Laboratory and Department of Physics and Astronomy, Iowa State University
    • Ames Laboratory/Iowa State University

  • J.C. Davis

    • Cornell University
    • Cornell University, Brookhaven National Lab, University of St. Andrews
    • Cornell University, University of St. Andrews, Brookhaven National Laboratory
    • Cornell U., BNL, U. of St. Andrews, U. of British Columbia