fig1

Figure 1. (A) Schematic diagram illustrating the generation of topologically non-trivial states through band inversion, adapted with permission^[29], Copyright © 2023 Wiley-Blackwell. (B) Band structure diagram of 2D topological insulators, adapted with permission^[30], Copyright © 2021 Springer Nature. (C) Schematic illustration of helical metallic edge states in a 2D topological insulator, where spin-up and spin-down electrons propagate in opposite directions along the edge, adapted with permission^[19], Copyright © 2022 Wiley-VCH.