Transport in Coherently Strained Thin Films of a 3D Dirac Semimetal

ORAL

Abstract

Cd3As2 is a 3D Dirac semimetal with degenerate band crossings at isolated points in k-space
(Dirac nodes). Most prior studies have focused on the electronic states of bulk single crystals.
Thin films of Cd3As2 allow for using heteroepitaxy approaches to control their electronic states.
Here, we present our studies of epitaxial thin films of Cd3As2 grown by molecular beam epitaxy
on (111) GaAs with relaxed InxGa1-xSb buffer layers. The composition of the InxGa1-xSb buffer
layers was varied to obtain layers that are lattice matched with the Cd3As2, as well as to obtain
tensile and compressively strained Cd3As2. We measured the strain in the Cd3As2 films using
high-resolution x-ray diffraction and showed that in-plane strains can be varied between 0.7%
to -0.9%, depending on the In-content of the buffer layers. The electrical transport properties
systematically vary with the magnitude of the film strain. We discuss the utility of strain
engineering to control the electronic states.

–

Presenters

  • Manik Goyal

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

Authors

  • Manik Goyal

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

  • 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

  • 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

  • Luca Galleti

    • Material Science, 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