Doping induced topological phase transition in WTe2

ORAL

Abstract

WTe2 exibits diverse phenomena including non-saturating magnetoresistance in its bulk with predicted type-II Weyl semimetal electronic structure, superconductivity under hydrostatic pressure, quantum spin hall insulator (QSHI) in its monolayer limit, and superconductivity in the gated monolayer. In many of these transformations, the tuning of the carrier density plays an important role. We report two non-monotonic changes in the electronic structure of WTe2 upon in-situ electron doping, realizing occupation near the chemical potential as a pathway for tuning structure and behavior of 2D materials. The first phase transition is understood in terms of the extra charge inducing a shear mode that triggers the recombination of the Weyl points, lifting the topological nature of the bands. This topological switching behavior is relevant for gate-controlled topological transistors or for producing lateral interfaces within a single material host via differential doping. The second phase transition is most consistent with a electrons in a 2D K-overlayer hybridizing with the WTe2 host, broadly relevant to understanding interactions with metallic contacts in devices constructed from 2D materials.

*UC Davis

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Presenters

  • Antonio Rossi

    • University of California, Davis
    • Physics, University of California, Davis

Authors

  • Antonio Rossi

    • University of California, Davis
    • Physics, University of California, Davis

  • Giacomo Resta

    • Physics, University of California, Davis

  • Seng Huat Lee

    • 2D Crystal Consortium, Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802, USA
    • Physics, The Pennsylvania State University
    • Pennsylvania State University
    • MRI, Penn State University

  • Ronald Redwing

    • Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania, 16802, USA
    • MRI, Penn State University

  • Chris Jozwiak

    • Advanced Light Source, Lawrence Berkeley National Lab
    • Lawrence Berkeley National Laboratory
    • Advanced Light Source, Lawrence Berkeley National Laboratory
    • Advanced Light Source, E. O. Lawrence Berkeley National Laboratory
    • ALS, Lawrence Berkeley National Lab
    • Advanced Light Source

  • Aaron Bostwick

    • Advanced Light Source, Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory
    • Advanced Light Source, Lawrence Berkeley National Lab
    • Advanced Light Source, E. O. Lawrence Berkeley National Laboratory
    • ALS, Lawrence Berkeley National Lab
    • Advanced Light Source

  • Eli Rotenberg

    • Advanced Light Source, Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory
    • Advanced Light Source, Lawrence Berkeley National Lab
    • Advanced Light Source, E. O. Lawrence Berkeley National Laboratory
    • ALS, Lawrence Berkeley National Lab
    • Advanced Light Source

  • Sergey Savrasov

    • University of California, Davis
    • Physics, University of California, Davis

  • Inna Vishik

    • University of California, Davis
    • Physics, University of California, Davis