Temperature-dependent Raman Spectroscopy of Doped and Undoped Topological Insulators

ORAL

Abstract

Topological insulators, materials whose bulk interior is insulating but have an unusual two dimensional electronic state at the surface, represent a new class of quantum materials now being intensively investigated. The objective of this work was to study how the introduction of magnetic dopants affect the Raman response of topological insulator thin films in terms of spectral peak position and linewidth. We performed temperature dependent Raman spectroscopy on 8nm thick doped and undoped samples of capped Bi2Te3 thin films grown by molecular beam epitaxy. The dopants used were Cr and V at 2% and 4% replacement of Bi. We describe the effect of this doping on the position, and full width at half maximum of the observed thin film spectra. From the analysis of the temperature dependent Raman response, we suggest that this behaviour can be understood in terms of doping-induced strain. This study revealed information about the lattice dynamical properties of Bi2Te3; in particular, how these properties evolve with the manipulation of metallic and transition metallic atoms in the topological insulator lattice.

*This work was supported by NSF Grant No. DMR-1231319

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Presenters

  • Pheona Williams

    • Physics, Howard University

Authors

  • Pheona Williams

    • Physics, Howard University

  • Yunbo Ou

    • Physics, Massachusetts Institute of Technology
    • Plasma Science and Fusion Center and Francis Bitter Magnet Laboratory
    • Plasma Science and Fusion Center and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology
    • State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University

  • Jeffrey Simpson

    • Engineering Physics, National Institute of Standards and Technology
    • Physics, Towson University
    • Physics, Astronomy, and GeoSciences, Towson University
    • Towson University
    • Department of Physics, Astronomy, and Geosciences, Towson University
    • Physics, Astronomy, and Geosciences, Towson Univ and NIST

  • Angela Hight Walker

    • Engineering Physics, National Institute of Standards and Technology
    • National Institute of Standards and Technology
    • NIST - Natl Inst of Stds & Tech
    • Physical Measurements Laboratory, National Institute of Standards and Technology
    • Physical Measurment Division, NIST
    • NIST -Natl Inst of Stds & Tech
    • Physical Measurement Laboratory, National Institute of Standards and Technology
    • NIST - National Institute of Standards and Technology
    • National Institute of Standards and Technology (NIST)
    • National Institute of Standards & Technology

  • Prabhakar Misra

    • Physics, Howard University

  • Joseph Checkelsky

    • Department of Physics, Massachusetts Institute of Technology
    • Massachusetts Inst of Tech-MIT
    • Physics, Massachusetts Institute of Technology
    • Massachusetts Institute of Technology
    • Physics, Massachusetts Inst of Tech-MIT

  • Jagadeesh Moodera

    • Physics, MIT
    • Physics, Massachusetts Institute of Technology
    • Department of Physics and Francis Bitter Magnet Lab, Massachusetts Institute of Technology
    • Department of Physics and Francis Bitter Magnet Lab, Massachusetts Institute of Technology,
    • Department of Physics, Massachusetts Institute of Technology
    • MIT
    • Department of Physics, Massachussetts Institute of Technology

  • Thomas Searles

    • Physics and Astronomy, Howard University
    • HOWARD UNIVERSITY
    • Physics, Howard University
    • Department of Physics & Astronomy, Howard University