Spin Pumping by Antiferromagnetic material

ORAL

Abstract

For a long time, spin-pumping is supposed to be impossible using antiferromagnetic materials (AFM) with compensated magnetization. We show that spin-pumping does not only exist in AFM with precessing staggered order, but is even stronger than its counterpart in ferromagnets. By calculating the scattering matrix of a normal metal/AFM interface based on a tight-binding model, we derive the pumped spin current in terms of the staggered order parameter and its time derivative. It is found that spin-pumping is of the same order of magnitude for both compensated and uncompensated interfaces. And the pumped spin current can be switched by changing the circular polarization of light exciting antiferromagnetic resonance, which introduces potential application. Besides spin current, we also define a new quantity--staggered spin current--and propose a novel pumping effect in AFM.

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Authors

  • Ran Cheng

    Department of Physics, University of Texas at Austin

  • Jiang Xiao

    Fudan Univ, Department of Physics, Fudan University

  • Arne Brataas

    Department of Physics and Astronomy, Norwegian University of Science and Technology, Department of Physics, Norwegian University of Science and Technology, NO-7491, Trondheim, Norway

  • 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