Anomalous Hall effect in ferromagnetic semiconductors: the case of Ga1-xMnxAs1-yPy

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.

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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