1. Bulk-edge correspondence in two-dimensional topological semimetals: A transfer matrix study of antichiral edge modes
- Author
-
Tohru Koma and Tomonari Mizoguchi
- Subjects
Physics ,Chern class ,Condensed Matter - Mesoscale and Nanoscale Physics ,Wave packet ,Transfer-matrix method (optics) ,FOS: Physical sciences ,02 engineering and technology ,Mathematical Physics (math-ph) ,Edge (geometry) ,021001 nanoscience & nanotechnology ,Topology ,01 natural sciences ,Transfer matrix ,Semimetal ,0103 physical sciences ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Multiple edges ,010306 general physics ,0210 nano-technology ,Electronic band structure ,Mathematical Physics - Abstract
We study edge modes in topological semimetals which have an energy band structure of ordinary semimetals but can be characterized by a Chern number. More specifically, we focus on a Qi-Wu-Zhang-type square-lattice model and a Haldane-type honeycomb model, both of which exhibit antichiral edge modes whose wave packets propagate in the same direction at both parallel edges of the strip. To obtain these analytical solutions of the edge modes, we apply the transfer matrix method which was developed in the previous work [Phys. Rev. B \textbf{101}, 014442 (2020)]. As a result, we show that the bulk-edge correspondence is broken down for a certain range of the model parameters. More precisely, when increasing the strength of a hopping amplitude of the Qi-Wu-Zhang-type model, the edge modes abruptly disappear, although the non-trivial Chern number does not change. In the Haldane-type model, for varying the model parameters, the edge modes do not necessarily disappear, and the non-trivial Chern number does not change. However, the energy spectral flows of the edge modes from the valence band to the conduction band are abruptly broken at a certain set of the model parameters., 14 pages, 8 figures. v3: added a discussion on the relation between the breakdown of the bulk-edge correspondence and the band touching, and typos corrected
- Published
- 2021