Dimensionality-Mediated Semimetal-Semiconductor Transition in Ultrathin PtTe<sub>2</sub> Films

ORAL

Abstract

Platinum ditelluride (PtTe2), a type-II Dirac semimetal in the bulk form, is made of Te-Pt-Te tri-atomic layers (TLs) loosely bonded together by van der Waals interactions. It remains semimetallic in ultrathin films down to just two TLs, but a further reduction of the film thickness to just a single TL induces a Lifshitz electronic transition to a semiconductor with a sizable gap. This transition is evidenced by experimental mapping of the band structure by angle-resolved photoemission spectroscopy for films of various thicknesses prepared by molecular beam epitaxy on a bilayer-graphene-terminated SiC substrate. Layer-by-layer evolution of the band structure is well resolved, which facilitates absolute layer counting. The measured semiconducting band structure for the single TL is in excellent agreement with theoretical calculations. Our results demonstrate a novel electronic transition at the single-layer, or two-dimensional limit through film thickness control.

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Presenters

  • Meng-Kai Lin

    • Department of Physics, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champaign

Authors

  • Meng-Kai Lin

    • Department of Physics, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champaign

  • Rovi Angelo B. Villaos

    • Physics, National Sun Yat-Sen University
    • Natl Sun Yat Sen Univ
    • Physics, National Sun Yat-sen University

  • Joseph Hlevyack

    • Department of Physics, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champaign

  • Peng Chen

    • School of Physics and Astronomy, Shanghai Jiao Tong University
    • University of Illinois at Urbana-Champaign

  • Ro-Ya Liu

    • Department of Physics, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champaign

  • Chia-Hsiu Hsu

    • Physics, National Sun Yat-Sen University
    • Natl Sun Yat Sen Univ
    • Physics, National Sun Yat-sen University

  • José Avila

    • Synchrotron SOLEIL
    • Synchrotron SOLEIL and Universite Paris-Saclay
    • SOLEIL

  • Sung-Kwan Mo

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

  • Feng-Chuan Chuang

    • Department of Physics, National Sun Yat-sen University
    • Physics, National Sun Yat-Sen University
    • Natl Sun Yat Sen Univ
    • National Sun Yat-Sen University
    • Physics, National Sun Yat-sen University

  • Tai-Chang Chiang

    • Department of Physics, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champaign