Anomalous Hall Effect in a 2DEG Containing Magnetic Impurities

ORAL

Abstract

The has been great interest recently in the role of electron spin in transport properties, specifically in the phenomena of the spin-Hall and anomalous-Hall effects. We present low- temperature transport measurements on a modulation-doped quantum well containing magnetic (Mn) impurities. The effect of the impurities is to cause a strong (free-spin) paramagnetic Zeeman- splitting of the carriers due to s-d exchange interactions. In recent measurements, we observe a Hall voltage that scales with the magnetic moment of the material, a signature of the anomalous-Hall effect. This is surprising, given that the material is not ferromagnetic and does not have a magnetically- ordered ground state. This has important implications for spin- transport in a large class of two-dimensional electron systems.

–

Authors

  • John Cumings

    • Stanford University

  • D. Goldhaber-Gordon

    • Stanford University
    • Department of Physics, Stanford University

  • Keh-Chiang Ku

    • Pennsylvania State University

  • Gang Xiang

  • N. Samarth

    • The Pennsylvania State University
    • Pennsylvania State University
    • Center for Spintronics and Quantum Computation, University of California-Santa Barbara and Materials Research Institute, Penn State University
    • Physics Dept., Penn State University
    • Materials Research Institute, Penn State University and Center for Spintronics and Quantum Computation, University of California-Santa Barbara