• Editors' Suggestion

Two-Dimensional Topological Insulator State in Cadmium Arsenide Thin Films

Alexander C. Lygo, Binghao Guo, Arman Rashidi, Victor Huang, Pablo Cuadros-Romero, and Susanne Stemmer
Phys. Rev. Lett. 130, 046201 – Published 24 January 2023
PDFHTMLExport Citation

Abstract

Two-dimensional topological insulators (2D TIs) are a highly desired quantum phase but few materials have demonstrated clear signatures of a 2D TI state. It has been predicted that 2D TIs can be created from thin films of three-dimensional TIs by reducing the film thickness until the surface states hybridize. Here, we employ this technique to report the first observation of a 2D TI state in epitaxial thin films of cadmium arsenide, a prototype Dirac semimetal in bulk form. Using magnetotransport measurements with electrostatic gating, we observe a Landau level spectrum and quantum Hall effect that are in excellent agreement with those of an ideal 2D TI. Specifically, we observe a crossing of the zeroth Landau levels at a critical magnetic field. We show that the film thickness can be used to tune the critical magnetic field. Moreover, a larger change in film thickness causes a transition from a 2D TI to a 2D trivial insulator, just as predicted by theory. The high degree of tunability available in epitaxial cadmium arsenide heterostructures can thus be used to fine-tune the 2D TI, which is essential for future topological devices.

  • Figure
  • Figure
  • Figure
  • Figure
  • Received 4 September 2022
  • Accepted 23 December 2022

DOI:https://doi.org/10.1103/PhysRevLett.130.046201

© 2023 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Alexander C. Lygo, Binghao Guo, Arman Rashidi, Victor Huang, Pablo Cuadros-Romero, and Susanne Stemmer*

  • Materials Department, University of California, Santa Barbara, California 93106-5050, USA

  • *Corresponding author. stemmer@mrl.ucsb.edu

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 130, Iss. 4 — 27 January 2023

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×