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Discovery of magnetic topological insulators using chemistry

ORAL

Abstract

In designing magnetic topological insulating states one often runs into mutually exclusive co-existence of topology and electron correlations. In order to achieve an intrinsic magnetic topological insulator state, there needs to be a separation between the density of states close to the Fermi level and the states from magnetism. Using this requirement, we identify Zintl compounds to be promising to find a sweet spot between topology and electron correlations. Zintl compounds have rocksalt-like charge separation between the cationic and anionic frameworks that are charge separated from one another. If the cationic framework is magnetic and the anionic framework is non-magnetic, consists of heavy atoms, and has covalent bonding, then these serve as essential structural motifs for magnetic topological insulators. Using this concept, we identify the Eu5M2X6 (M = Ga,In,Tl, X = Sb,Bi) family of materials as a rich source of topologically trivial and non-trivial insulators. In this work we will present the synthesis, magnetism, optical and transport behavior of members of this family with an aim of identifying an intrinsic axion insulator.

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Presenters

  • Tanya Berry

    Johns Hopkins University

Authors

  • Tanya Berry

    Johns Hopkins University

  • Nicodemos Varnava

    Rutgers University, New Brunswick, Rutgers University

  • Vincent C Morano

    Johns Hopkins University

  • Jonathan Gaudet

    National Institute of Standards and Technology, Johns Hopkins University

  • Rishi Bhandia

    Johns Hopkins University

  • Anaelle Legros

    Johns Hopkins University

  • Thomas J Halloran

    Johns Hopkins University

  • Chris J Lygouras

    Johns Hopkins University, John Hopkins University

  • Will Liang

    Johns Hopkins University

  • N. P Armitage

    Johns Hopkins University, Johns Hopikns Univ., The Institute for Quantum Matter, Department of Physics and Astronomy, The Johns Hopkins University

  • Guangyong Xu

    NIST

  • Jeffrey W Lynn

    National Institute of Standards and Tech, National Institute of Standards and Technology

  • David Vanderbilt

    Rutgers University, Rutgers University, New Brunswick

  • Collin L Broholm

    Johns Hopkins University, John Hopkins University

  • Tyrel M McQueen

    Johns Hopkins University, Department of Chemistry, The Johns Hopkins University