Epitaxial growth and transport studies of [001]-oriented cadmium arsenide, a 3D Dirac semimetal

ORAL

Abstract

In the 3D Dirac semimetal cadmium arsenide, the Dirac nodes fall along the kz axis and are stabilized by the fourfold rotation symmetry of the tetragonal crystal structure. However, the easy growth direction is along [221], a lower-symmetry direction. In [221]-oriented thin films, epitaxial strain and finite thickness reduce the symmetry of the kz axis and can cause the Dirac nodes to vanish. Here, we report the first growth and electronic transport studies of [001]-oriented thin films (i.e. those grown parallel to kz), in which the fourfold axis is preserved by the sample geometry. These films are grown by molecular beam epitaxy on a III–V substrate with a tunable buffer layer. Low-temperature mobilities in these films greater than 17,000 cm2/Vs permit a comparison with the more widely studied [221]-oriented films to elucidate the role of surface states in the electronic transport.

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Presenters

  • David Kealhofer

    Department of Physics, University of California Santa Barbara, Univ of California - Santa Barbara, Physics, University of California, Santa Barbara, Department of Physics, University of California, Santa Barbara

Authors

  • David Kealhofer

    Department of Physics, University of California Santa Barbara, Univ of California - Santa Barbara, Physics, University of California, Santa Barbara, Department of Physics, University of California, Santa Barbara

  • Luca Galletti

    ENMT, Materials Department, Univeristy of California Santa Barbara, Materials, University of California, Santa Barbara, Materials Department, University of California Santa Barbara

  • Manik Goyal

    Materials, University of California, Santa Barbara, Material Science, University of California, Santa Barbara

  • Honggyu Kim

    ENMT, Materials Department, Univeristy of California Santa Barbara, Univ of California - Santa Barbara, Materials, University of California, Santa Barbara

  • Salva Rezaie

    Materials, University of California, Santa Barbara

  • Timo Schumann

    ENMT, Materials Department, Univeristy of California Santa Barbara, Univ of California - Santa Barbara, Materials, University of California, Santa Barbara, Material Science, University of California, Santa Barbara, Materials Department, University of California Santa Barbara

  • Susanne Stemmer

    ENMT, Materials Department, Univ of California - Santa Barbara, Univ of California - Santa Barbara, UC Santa Barbara, ENMT, Materials Department, Univeristy of California Santa Barbara, Materials, University of California, Santa Barbara, Material Science, University of California, Santa Barbara, Materials Department, University of California Santa Barbara, Materials Department, Univ of California - Santa Barbara, Materials, Univ of California - Santa Barbara, Materials, Univ of California, Santa Barbara