Observation of a Smoothly Tunable Dirac Point in Ge(Bi<sub>x</sub>Sb<sub>1-x</sub>)<sub>2</sub>Te<sub>4</sub>

ORAL

Abstract

Next-generation topological devices use topologically protected surface states to drive electronic transport. In this study, we examine Ge(BixSb1-x)2Te4, a tunable topological system, for a range of x values from 0 to 1 using a combination of Fourier-Transform Scanning Tunneling Spectroscopy (FT-STS) and Angle-Resolved Photoemission Spectroscopy (ARPES). We show that the Dirac point changes linearly with x, crossing the Fermi energy at x = 0.7. This novel observation of a smoothly tunable, isolated Dirac point traversing the topological transport regime and having strong linear dependence with substitution can be critical in designing new topological spintronics applications.

*The STM work was supported by a grant from the U.S. Department of Energy (DOE), Office of Science (OS), Office of Basic Energy Sciences, under award No. DE-SC0014335. We acknowledge partial support from the Gordon and Betty Moore Foundation's EPiQS Initiative through grant GBMF4860. This work was carried out, in part, at the Seitz Materials Research Laboratory Central Research Facilities, at the University of Illinois at Urbana-Champaign. The ARPES work is supported by the U.S. Department of Energy (DOE), Office of Science (OS), Office of Basic Energy Sciences, Division of Materials Science and Engineering, under Grant No. DE-FG02-07ER46383. This ARPES research used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under contract No. DE-AC02-05CH11231. In addition, we acknowledge support from the Taiwan Ministry of Science and Technology (MOST), under Grant No. 109-2112-M-001-014-MY3 and Grant No. MOST-108-2112-M-001-049-MY2.

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Publication: https://arxiv.org/abs/2101.05166

Presenters

  • Arjun Raghavan

    • University of Illinois at Urbana-Champaign
    • Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA

Authors

  • Arjun Raghavan

    • University of Illinois at Urbana-Champaign
    • Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA

  • Sean T Howard

    • University of Illinois at Urbana-Champaign

  • Arjun Raghavan

    • University of Illinois at Urbana-Champaign
    • Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA

  • Davide Iaia

    • University of Illinois at Urbana-Champaign

  • Caizhi Xu

    • University of Illinois at Urbana-Champaign

  • David Flototto

    • University of Illinois at Urbana-Champaign

  • Man-Hong Wong

    • University of Illinois at Urbana-Champaign

  • Sung-Kwan Mo

    • Lawrence Berkeley National Laboratory

  • Bahadur Singh

    • Tata Institute of Fundamental Research
    • Tata Institute for Fundamental Research
    • TIFR
    • Tata Institute of Fundamental Research, Mumbai
    • Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai, India

  • Raman Sankar

    • Academia Sinica
    • Institute of Physics, Academia Sinica

  • Hsin Lin

    • Academia Sinica
    • Institute of Physics, Academia Sinica, Taiwan

  • Tai-Chang Chiang

    • University of Illinois at Urbana-Champaign

  • Vidya Madhavan

    • University of Illinois at Urbana-Champaign
    • Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA