Two phase transitions driven by surface electron doping in WTe<sub>2</sub>

ORAL

Abstract

Topological Weyl semimetal WTe2 is a Van der Waals crystal that gained attention for its large and nonsaturating magnetoresistance, which has been attributed to perfect compensation of electron and hole pockets in the bulk electronic structure. Although, altering the electron hole-balance via electron doping is not predicted to yield a structural phase transition, it is reasonable to expect a different electronic ground state with respect to the compensated system.
Here we show via angle resolved photoemission spectroscopy (ARPES), that surface electron doping in WTe2 can induce a shear displacement in the top layers, producing a crystal structure locally similar to a polytype typically not encountered in ambient conditions. This phase transition is evidenced by pronounced changes in low-energy surface electronic structure with support from first-principles calculations. A second phase transition at higher doping levels is associated with an interplay between hybridization with dopant bands and Stark effect that affects higher-energy band structure.
[1] Rossi et al., PHYSICAL REVIEW B102, 121110(R) (2020)

*UC Davis Startup funds and the AlfredP. Sloan Foundation (FG-2019-12170)

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Presenters

  • Antonio Rossi

    • Lawrence Berkeley National Laboratory
    • University of California, Davis
    • Lawrence Berkeley National Lab, Advanced Light Source
    • Advanced Light Source, Lawrence Berkeley National Laboratory

Authors

  • Antonio Rossi

    • Lawrence Berkeley National Laboratory
    • University of California, Davis
    • Lawrence Berkeley National Lab, Advanced Light Source
    • Advanced Light Source, Lawrence Berkeley National Laboratory

  • Giacomo Resta

    • Physics and Astronomy, University of California, Davis

  • Seng Huat Lee

    • Pennsylvania State University
    • Department of Physics, Pennsylvania State University
    • Physics, The Pennsylvania State University
    • 2D Crystal Consortium, Materials Research Institute, Penn State University
    • Materials Research Institute, Pennsylvania State University

  • Ronald Dean Redwing

    • Department of Materials Science and Engineering, Pennsylvania State University
    • 2D Crystal Consortium, Materials Research Institute, Penn State University
    • Materials Research Institute, Pennsylvania State University

  • Chris Jozwiak

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

  • Aaron Bostwick

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

  • Eli Rotenberg

    • Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National Lab, Advanced Light Source
    • Advanced Light Source, Lawrence Berkeley National Laboratory
    • Advanced Light Source
    • Advanced Light Source, Lawrence Berkeley National Lab
    • LBNL

  • Sergey Savrasov

    • UC Davis
    • Physics and Astronomy, University of California, Davis
    • University of California, Davis

  • Inna Vishik

    • University of California, Davis
    • Physics and Astronomy, University of California, Davis