Recent Results on Topological Phase Transition and Texture Inversion in Tunable Topological Insulators

ORAL

Abstract

The recently discovered three-dimensional or bulk topological insulators are expected to exhibit exotic quantum phenomena. It is believed that a trivial insulator can be twisted into a topological state by modulating the spin-orbit interaction or the crystal lattice, driving the system through a topological quantum phase transition. By directly measuring the topological quantum numbers, we report the observation of a phase transition in a tunable spin-orbit system, BiTl(S$_{1-\delta}$Se$_{\delta}$)$_2$, in which the topological state formation is visualized (S.-Y. Xu \textit{et al}., \textit{Science} (2011)). In the topological state, vortex-like polarization states are observed to exhibit three-dimensional vectorial textures, which collectively feature a chirality transition as the spin momentum-locked electrons on the surface go through the zero carrier density point. Such phase transition and texture inversion can be the physical basis for observing fractional charge ($\pm$e/2) and other fractional topological phenomena. We also present some of our recent results that reveal further novel spin and electronic properties of the system close to the critical point of the topological phase transition.

*We acknowledge support from DOE/BES.

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Authors

  • Su-Yang Xu

    • Princeton University
    • Dept. of Physics, Princeton University, Princeton, NJ 08544
    • Joseph Henry Laboratory and Dept. of Physics, Princeton University

  • Yuqi Xia

    • Princeton University

  • L.A. Wray

    • Lawrence Berkeley National Laboratory
    • Joseph Henry Laboratory and Dept.of Physics, Princeton University; Advanced Light Source, Lawrence Berkeley National Laboratory

  • Shuang Jia

    • Princeton University
    • Department of Chemistry, Princeton University

  • Fabian Meier

    • Paul Scherrer Institute

  • Jan Hugo Dil

    • Paul Scherrer Institute

  • Jurg Osterwalder

    • Univerisity of Zurich

  • Bartosz Slomski

    • Paul Scherrer Institute

  • Arun Bansil

    • Northeastern University
    • Northeastern U.
    • Department of Physics, Northeastern University

  • Hsin Lin

    • Northeastern U.
    • Northeastern University
    • Department of Physics, Northeastern University

  • Robert Cava

    • Chemistry department, Princeton University
    • Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
    • Princeton University
    • Department of Chemistry, Princeton University

  • M. Zahid Hasan

    • Princeton University
    • Dept. of Physics, Princeton University, Princeton, NJ 08544
    • Princeton University Physics
    • Joseph Henry Laboratory and Dept. of Physics, Princeton University