Interplay of quantum oscillations and ferromagnetism in magnetic topological insulators

ORAL

Abstract

Ferromagnetic topological insulators are of interest because of the experimental realization of quantized anomalous Hall effect. Here we report measurements on ebeam lithographically contacted devices of Vanadium doped (Bi,Sb)$_2$Te$_3$. These devices exhibit unconventional Shuvnikov­-de Haas type oscillations at zero bias that have a strong dependence on applied bias voltage. These magneto­-oscillations have been observed with both superconducting and normal metal contacts. Intriguingly, these oscillations are observed to be most prominent in submicron devices and weaken significantly in wider junctions. Logarithmic dependence of the longitudinal resistance and anomalous Hall resistance is observed on temperature and applied bias voltage. A phenomenological model is presented to explain the various experimental observations.

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Authors

  • D. Nandi

    Harvard University, Department of Physics, Harvard University, Cambridge, MA, 02138, Department of Physics, Harvard University, Cambridge, MA 02138

  • K. Shain

    Department of Physics, Harvard University, Cambridge, MA, 02138, Department of Physics, Harvard University, Cambridge, MA 02138

  • G.H. Lee

    Harvard University, Cambridge, USA, Department of Physics, Harvard University, Cambridge, MA, 02138, Department of Physics, Harvard University, Cambridge, MA 02138

  • Cui-Zu Chang

    Massachusetts Institute of Technology, Pennsylvania State University, The Penn State University & Massachusetts Institute of Technology, MIT&The Penn State University, Francis Bitter Magnet Lab, Massachusetts Institute of Technology, Cambridge, MA, 02139, Francis Bitter Magnet Lab, Massachussetts Institute of Technology, Cambridge, MA 02139

  • K. Huang

    Department of Physics, Harvard University, Cambridge, MA, 02138, Department of Physics, Harvard University, Cambridge, MA 02138

  • J. Ward

    Department of Physics, Harvard University, Cambridge, MA, 02138, Department of Physics, Harvard University, Cambridge, MA 02138

  • J.S. Moodera

    Dept. of Physics, Francis Bitter Magnet Lab, Plasma Science and Fusion Center, MIT, Massachusetts Institute of Technology, Dept. of Physics and Francis Bitter Magnet Lab, MIT, MIT, Francis Bitter Magnet Lab, Massachusetts Institute of Technology, Cambridge, MA, 02139, Francis Bitter Magnet Lab, Massachussetts Institute of Technology, Cambridge, MA 02139

  • P. Kim

    Harvard University, Department of Physics, Harvard University, Department of Physics, Harvard University, Cambridge, MA 02138, US, Harvard University, department of Physics, Harvard University, Department of Physics, Department of Physics, Harvard University, Cambridge, MA, 02138, Department of Physics, Harvard University, Cambridge, MA 02138

  • A. Yacoby

    Harvard University, Harvard University, Cambridge USA., Department of Physics, Harvard University, Department of Physics, Harvard University, Cambridge, MA, 02138, Department of Physics, Harvard University, Cambridge, MA 02138