Anomalous Hall effect in ferromagnetic semiconductors: the case of Ga<sub>1-<i>x</i></sub>Mn<i><sub>x</sub></i>As<sub>1-<i>y</i></sub>P<i><sub>y</sub></i>

ORAL

Abstract

While the carrier-mediated ferromagnetism on GaMnAs has been thoroughly studied in the past, the origin of anomalous Hall effect (AHE) in magnetic III-V systems remains elusive, particularly for the quaternary GaMnAsP. We have thus measured the AHE in a series of GaMnAsP alloys grown by molecular beam epitaxy with varying amounts of phosphorus, both as-grown and annealed. We carried out extensive measurements of transverse and longitudinal resistivity as a function of both magnetic field and temperature. By applying a modified Brillouin-Weiss model for the magnetization, we decompose the AHE into an “extrinsic” contribution (due to scattering) and a dominating “intrinsic” contribution (due to the Berry curvature). Our data strongly indicates that the influence of the intrinsic mechanism is important in samples with low phosphorus content. Importantly, we find that the amount of the intrinsic contribution is tunable by controlling the phosphorus concentration in GaMnAsP alloys. Consequently, our results suggest that the valence bands of III-Mn-V compounds could host a strong Berry curvature, possibly driven by the strain effects that are known to occur in GaMnAsP grown on GaAs.

*Work supported by NSF Grant DMR 1905277.

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Presenters

  • Xinyu Liu

    • University of Notre Dame
    • Physics, University of Notre Dame
    • Department of Physics, University of Notre Dame

Authors

  • Xinyu Liu

    • University of Notre Dame
    • Physics, University of Notre Dame
    • Department of Physics, University of Notre Dame

  • Logan Riney

    • University of Notre Dame
    • Physics, University of Notre Dame
    • Department of Physics, University of Notre Dame

  • Jiashu Wang

    • University of Notre Dame
    • Physics, University of Notre Dame
    • Department of Physics, University of Notre Dame

  • Sining Dong

    • University of Notre Dame
    • School of Electronic Science and Engineering, Nanjing University

  • Lei Guo

    • Shanghai Institute of Ceramics, Chinese Academy of Sciences

  • Ren-Kui Zheng

    • Shanghai Institute of Ceramics, Chinese Academy of Sciences

  • Xiang Li

    • University of Notre Dame
    • Physics, University of Notre Dame

  • Seul-Ki Bac

    • University of Notre Dame
    • Physics, University of Notre Dame
    • Department of Physics, University of Notre Dame

  • Jacek Kossut

    • Institute of Physics, Polish Academy of Sciences

  • Malgorzata Dobrowolska

    • University of Notre Dame
    • Physics, University of Notre Dame
    • Department of Physics, University of Notre Dame

  • J K Furdyna

    • University of Notre Dame
    • Physics, University of Notre Dame
    • Department of Physics, University of Notre Dame

  • Yi-Ting Hsu

    • Physics, University of Notre Dame
    • Department of Physics, University of Notre Dame

  • Badih A Assaf

    • University of Notre Dame
    • Physics, University of Notre Dame
    • Department of Physics, University of Notre Dame