Abstract
The recent discovery of axion states in materials such as antiferromagnetic topological insulators has boosted investigations of the magnetoelectric response in topological insulators and their promise towards realizing dissipationless topological electronics. In this paper, we develop a tight-binding methodology to explore the emergence of axion states in in proximity to magnetic insulators on the top and bottom surfaces. The topological protection of the surface states is lifted by a time-reversal-breaking perturbation due to the proximity of a magnetic insulator, and a gap is opened on the surfaces, giving rise to half-quantized Hall conductance and a zero Hall plateau—evidencing an axion insulator state. We developed a real-space tight-binding Hamiltonian for using first-principles data. Transport properties of the system were obtained within the Landauer-Büttiker formalism, and we discuss the creation of axion states through Hall conductance and a zero Hall plateau at the surfaces, as a function of proximitized magnetization and corresponding potentials at the surfaces, as well as the thickness of the topological insulator.
5 More- Received 5 April 2022
- Revised 27 June 2022
- Accepted 12 July 2022
- Corrected 23 August 2022
DOI:https://doi.org/10.1103/PhysRevMaterials.6.074205
©2022 American Physical Society
Physics Subject Headings (PhySH)
Corrections
23 August 2022
Correction: A minor typographical error in the equation given in item (i) of the list below the first paragraph of Sec. II has been fixed.