Topological invariant and domain connectivity in moiré materials

Ikuma Tateishi and Motoaki Hirayama
Phys. Rev. B 107, 125308 – Published 31 March 2023

Abstract

Recently, a moiré material has been proposed in which multiple domains of different topological phases appear in the moiré unit cell due to a large moiré modulation. Topological properties of such moiré materials may differ from those of the original untwisted layered material. In this paper, we study how the topological properties are determined in moiré materials with multiple topological domains. We show a correspondence between the topological invariant of moiré materials at the Fermi level and the topology of the domain structure in real space. We also find a bulk-edge correspondence that is compatible with a continuous change in the truncation condition, which is specific to moiré materials. We demonstrate these correspondences in the twisted Bernevig-Hughes-Zhang model that describes general Z2-indicated topological insulator phases, by tuning its domain structure in the moiré unit cell. The obtained result can only be used to determine the topology at the Fermi level in the charge-neutral condition, but it can be combined with the traditional Wilson loop analysis to determine topologies of other gaps around. These results give a feasible method to evaluate a topological invariant for all occupied bands of a moiré material and contribute to the design of topological moiré materials and devices.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
5 More
  • Received 21 December 2022
  • Revised 8 March 2023
  • Accepted 15 March 2023

DOI:https://doi.org/10.1103/PhysRevB.107.125308

©2023 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Ikuma Tateishi1,* and Motoaki Hirayama2,1,†

  • 1RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan
  • 2Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan

  • *ikuma.tateishi@riken.jp
  • hirayama@ap.t.u-tokyo.ac.jp

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 107, Iss. 12 — 15 March 2023

Reuse & Permissions
Access Options
CHORUS

Article part of CHORUS

Accepted manuscript will be available starting 30 March 2024.
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×