Two-dimensional states in confined thin films of the three-dimensional Dirac semimetal Cd3As2 are probed by transport and capacitance measurements under applied magnetic and electric fields. The results establish the two-dimensional Dirac electronic spectrum of these states. We observe signatures of p-type conduction in the two-dimensional states as the Fermi level is tuned across their charge neutrality point and the presence of a zero energy Landau level, all of which indicate topologically non-trivial states. The resistance at the charge neutrality point is approximately h/e2 and increases rapidly under the application of a magnetic field. The results open many possibilities for gate-tunable topological devices and for the exploration of novel physics in the zero energy Landau level.
@article{arxiv.1802.09494,
title = {Two-Dimensional Dirac Fermions in Thin Films of Cd3As2},
author = {Luca Galletti and Timo Schumann and Omor F. Shoron and Manik Goyal and David A. Kealhofer and Honggyu Kim and Susanne Stemmer},
journal= {arXiv preprint arXiv:1802.09494},
year = {2018}
}