Controlling magnetic order, magnetic anisotropy, and band topology in the semimetals Sr(Mn<sub>0.9</sub>Cu<sub>0.1</sub>)Sb<sub>2</sub> and Sr(Mn<sub>0.9</sub>Zn<sub>0.1</sub>)Sb<sub>2</sub>

ORAL

Abstract

Neutron diffraction and magnetic susceptibility studies show that orthorhombic single-crystals of the topological semimetals Sr(Mn0.9Cu0.1)Sb2 and Sr(Mn0.9Zn0.1)Sb2 undergo three-dimensional C-type AFM ordering at a significantly lower TN than that of the parent compound SrMnSb2. Magnetization versus magnetic field (applied perpendicular to the MnSb planes) measurements below TN exhibit dHvA oscillations for the Sr(Mn0.9Zn0.1)Sb2, but not for the Sr(Mn0.9Cu0.1)Sb2. This suggests that doping with Cu for Mn either substantially changes the electronic band structure; or that the Cu sites are strong scatterers of carriers, which significantly shortens the mean free path, and diminishes the quantum oscillations. DFT calculations including spin-orbit coupling find that doping with either Cu or Zn tunes the electronic bands near the Fermi level, resulting in different band topologies and semimetallicity. These calculations rationalize the experimental results by showing that the parent and Zn-doped compounds have coexistence of electron and hole pockets with an open Dirac cone around the Y-point, whereas the Cu-doped compound has dominant hole pockets around the Fermi level with a distorted Dirac cone.

*Supported by the US Department of Energy under Contract No. DE-AC02-07CH11358.

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Presenters

  • FARHAN ISLAM

    • Ames Lab

Authors

  • FARHAN ISLAM

    • Ames Lab

  • Renu Choudhary

    • Ames Lab

  • Yong Liu

    • Ames Lab
    • Institute of Physics, Ecole Polytechnique Federale de Lausanne
    • Ames Laboratory

  • Benjamin Ueland

    • Ames Lab
    • Physics and Astronomy, Iowa State University/Ames Laboratory
    • Division of Materials Science & Engineering, Ames Laboratory
    • Ames Laboratory and Iowa State University, Ames, IA USA 50011
    • Ames Laboratory/Iowa State University

  • Durga Paudyal

    • Ames Lab
    • Iowa State University, Ames Laboratory, Department of Electrical and Computer Engineering
    • Iowa State University, Ames Laboratory and Department of Electrical and Computer Engineering
    • Ames Laboratory, Department of Electrical and Computer Engineering, Iowa State University, USA.
    • Ames Laboratory, Department of Electrical and Computer Engineering, Iowa State University
    • Ames Laboratory, Electrical and Computer Engineering, Iowa State University
    • Ames Lab, Iowa State University
    • Ames Laboratory

  • Thomas W Heitmann

    • University of Missouri
    • University of Missouri Research Reactor
    • The Missouri Research Reactor, University of Missouri, Columbia, Missouri
    • Missouri Research Reactor, University of Missouri
    • University of Missouri Research Reactor, University of Missouri

  • Robert J McQueeney

    • Ames Lab
    • Physics and Astronomy, Iowa State University/Ames Laboratory
    • Department of Physics and Astronomy, Ames Laboratory, Iowa State University
    • Ames Lab/Iowa State
    • Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011, USA
    • Iowa State University
    • Ames Laboratory and Iowa State University, Ames, IA USA 50011
    • Ames Laboratory/Iowa State University

  • David Vaknin

    • Ames Lab
    • Physics and Astronomy, Iowa State University/Ames Laboratory