Anomalous Hall Effect Arising form Noncollinear Antiferromagnetism: Mn3Ir as an Example

ORAL

Abstract

Ferromagnetic conductors exhibit anomalous contributions to their transverse (Hall) conductivities that cannot be attributed to Lorentz force on electrons from a magnetic field. The anomalous Hall conductivity is often assumed to be proportional to the magnetization, allowing transport measurements to be used in spintronics as a convenient proxy for magnetometry. However, simple symmetry arguments demonstrate that the anomalous Hall effect requires only time-reversal symmetry breaking and spin-orbit coupling, not net magnetization, and we illustrate our ideas by examining a toy model of noncollinear antiferromagnet on a two-dimensional kagome lattice. This is further backed up with a realistic example based on first-principles calculations, predicting that single-crystals of Mn$_3$Ir, a high-temperature antiferromagnet commenly used in spin-valve devices, have large anomalous Hall conductivities. Hua Chen, Qian Niu, and Allan H. MacDonald, arXiv:1309.4041

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Authors

  • Hua Chen

    University of Texas at Austin, Department of Physics, The University of Texas at Austin, Austin, TX, 78712, The University of Texas at Austin

  • Qian Niu

    University of Texas at Austin, UT Austin, Department of Physics, University of Texas at Austin, University of Texas at Austin, Austin, Texas 78712, USA, The University of Texas at Austin, Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA

  • Allan MacDonald

    The University of Texas at Austin, Department of Physics, University of Texas at Austin, Austin, Texas 78712-1081, USA, Department of Physics, The University of Texas at Austin, Austin, TX, 78712, Department of Physics, University of Texas at Austin, University of Texas at Austin, University of Texas at Austin, Austin, Texas 78712, USA, UT Austin, Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA