Exploration of topological electronic structures in bismuth halide series

ORAL

Abstract

Quasi-one-dimensional bismuth halides, Bi4X4 (X = I, Br), constitute a promising material platform to realize various non-trivial topological phases. Bi4X4 can be categorized by its stacking along c axis. Weak topological insulators (TIs) in single-layer stacking, high-order TI in double stacking, and topological phases transitions opportunities in between are on the table. In addition, discovery of gate-tunable Josephson supercurrent as well as existence of electronic instabilities driven by topological surface states (TSS) bring Bi4X4 a fertile candidate to study topological many-body physics and emergent quantum physics. In this talk, I will present experimental characterizations for electronic structures among the Bi4X4 series in terms of angle-resolved photoemission spectroscopy (ARPES), which is smoking-gun evidence to identify TSS and instabilities in them. State-of-the-art ARPES at synchrotrons enable us to explore (001) and (100) surfaces distinguishably, thus can provide reliable topological characterizations among the series. Taking advantages of it, we discovered a room-temperature topological phase transition between weak TI and high-order TI, an ideal weak TI with spin-polarized electronic instabilities derived from TSS within bulk gap, and gapped TSS due to hinge states in high-order TI. Future efforts to induce topological phase transitions will be also discussed.

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Presenters

  • Ji Seop Oh

    • University of California Berkeley

Authors

  • Ji Seop Oh

    • University of California Berkeley

  • Tianyi Xu

    • University of Texas at Dallas

  • Nikhil Dhale

    • The University of Texas at Dallas

  • Jianwei Huang

    • Rice University

  • Sheng Li

    • University of Texas at Dallas

  • Chiho Yoon

    • University of Texas at Dallas
    • Seoul Natl Univ

  • Chao Lei

    • University of Texas at Austin

  • Hanlin Wu

    • University of Texas at Dallas

  • Makoto Hashimoto

    • SLAC - Natl Accelerator Lab

  • Donghui Lu

    • SLAC - Natl Accelerator Lab

  • Jonathan D Denlinger

    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory, Berkeley, California

  • Christopher Jozwiak

    • Lawrence Berkeley National Laboratory
    • LBNL
    • The Advanced Light Source
    • lawrence berkeley national lab
    • Lawrence Berkeley National Lab
    • Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America
    • Advanced Light Source, Lawrence Berkeley National Lab

  • Aaron Bostwick

    • Lawrence Berkeley National Laboratory
    • LBNL
    • The Advanced Light Source
    • lawrence berkeley national lab
    • Lawrence Berkeley National Lab
    • Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America
    • Advanced Light Source, Lawrence Berkeley National Lab

  • Eli Rotenberg

    • Lawrence Berkeley National Laboratory
    • Advanced Light Source, Lawrence Berkeley National Lab

  • Chun Ning Lau

    • Ohio State Univ - Columbus

  • Bing Lv

    • University of Texas at Dallas

  • Fan Zhang

    • The University of Texas at Dallas
    • UT Dallas

  • Robert J Birgeneau

    • University of California, Berkeley

  • Ming Yi

    • Rice University