Observation of a topological 3D Dirac semimetal phase in high-mobility Cd$_{3}$As$_{2}$

ORAL

Abstract

Experimental identification of three-dimensional (3D) Dirac semimetals in solid state systems is critical for realizing exotic topological phenomena and quantum transport. Using high-resolution angle-resolved photoemission spectroscopy, we performed systematic electronic structure studies on well-known compound Cd$_{3}$As$_{2}$. For the first time, we observe a highly linear bulk Dirac cone located at the Brillouin zone center projected onto the (001) surface, which is consistent with a 3D Dirac semimetal phase in Cd$_{3}$As$_{2}$. Remarkably, an unusually high Dirac Fermion velocity is seen in samples where the mobility far exceeds 20,000 cm$^{2}$/V.s suggesting that Cd$_{3}$As$_{2}$ can be a promising candidate as a hypercone analog of graphene in many device-applications, which can also incorporate topological quantum phenomena in a large gap setting.

*This work is primarily supported by U.S. DOE and Princeton University.

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Authors

  • Madhab Neupane

    • Princeton University, USA
    • Dept. of Physics, Princeton University, USA
    • Dept. of Physics, Princeton University, NJ, USA

  • S.-Y. Xu

    • Princeton University, USA

  • R. Sankar

    • National Taiwan University, Taiwan

  • N. Alidoust

    • Princeton University, USA

  • G. Bian

    • Princeton University, USA

  • Chang Liu

    • Princeton University, USA

  • I. Belopolski

    • Princeton University, USA

  • T.-R. Chang

    • National Tsing Hua University, Taiwan

  • H.-T. Jeng

    • National Tsing Hua University \& Institute of Physics, Academia Sinica, Taiwan

  • H. Lin

    • National University of Singapore, Singapore

  • A. Bansil

    • Northeastern University, USA

  • Fangcheng Chou

    • National Taiwan University, Taiwan

  • M.Z. Hasan

    • Princeton University \& Princeton Center for Complex Materials, PRISM, USA