Observation of the Quantum Hall Effect in Confined Films of the Three-Dimensional Dirac Semimetal ${\mathrm{Cd}}_{3}{\mathrm{As}}_{2}$

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Observation of the Quantum Hall Effect in Confined Films of the Three-Dimensional Dirac Semimetal ${Cd}_{3} {As}_{2}$

Timo Schumann, Luca Galletti, David A. Kealhofer, Honggyu Kim, Manik Goyal, and Susanne Stemmer

Phys. Rev. Lett. 120, 016801 – Published 3 January 2018

Abstract

The magnetotransport properties of epitaxial films of ${Cd}_{3} {As}_{2}$ , a paradigm three-dimensional Dirac semimetal, are investigated. We show that an energy gap opens in the bulk electronic states of sufficiently thin films and, at low temperatures, carriers residing in surface states dominate the electrical transport. The carriers in these states are sufficiently mobile to give rise to a quantized Hall effect. The sharp quantization demonstrates surface transport that is virtually free of parasitic bulk conduction and paves the way for novel quantum transport studies in this class of topological materials. Our results also demonstrate that heterostructuring approaches can be used to study and engineer quantum states in topological semimetals.

Received 16 October 2017

DOI:https://doi.org/10.1103/PhysRevLett.120.016801

Physics Subject Headings (PhySH)

Quantum Hall effect

Dirac semimetal Thin films

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Timo Schumann^1,*, Luca Galletti¹, David A. Kealhofer², Honggyu Kim¹, Manik Goyal¹, and Susanne Stemmer^1,†

¹Materials Department, University of California, Santa Barbara, California 93106-5050, USA
²Department of Physics, University of California, Santa Barbara, California 93106-9530, USA