Static Nematic Electronic Structure in the ``Parent'' State of the Iron-Based Superconductor Ca(Fe$_{1-x}$Cox)$_{2}$As$_{2}$

ORAL

Abstract

We use spectroscopic imaging STM to study the electronic structure of CaFe$_{1.94}$Co$_{0.06}$As$_{2}$ in the antiferromagnetic and orthorhombic `parent' state from which the iron-based high temperature superconductivity emerges with increased carrier density. We find static unidirectional nanostructures self similar at $\sim $ 8 a$_{FeFe}$, aligned along the crystalline a (AFM) axis. This introduces an unidirectionality (nematicity) much stronger than one could expect from the musicale lattice distortion; on a lengthscale different than the AFM lengthscale.

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Authors

  • Milan P. Allan

    Cornell University

  • Tien-Ming Chuang

    Cornell University

  • 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