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