Snake states at domain walls of magnetic topological insulators
Phys. Rev. B 112, 115302 – Published 8 September, 2025
DOI: https://doi.org/10.1103/yjxb-hl6h
Abstract
The transport properties of domain wall states in a magnetic topological insulator thin film-based heterostructure are highly sensitive to domain wall configurations. In this work, we identify the existence of the snake state at the magnetic domain wall via electronic transport calculations. We have found the following. (1) The transmission coefficient oscillates periodically with the number of snake state wave cycles, while the wavelength of the snake state is determined by the domain wall profile and its orientation. (2) The transmission through either a slanted or a smoothly curved domain wall is exclusively governed by the domain wall's relative positioning of the endpoints and is impervious to its deformation, a characteristic shared with the electrostatic field. (3) Under heavy disorder, the current splits equally at the termination of the domain wall, independent of the domain wall's profile. (4) The snake state transport through a magnetic domain of finite width can be explained by the combination of two domain walls connected in series. This study offers valuable insights into transport and phase transitions in magnetic topological insulators thin films with complex domain structures.
