Edge on-site potential effects in a honeycomb topological magnon insulator

TL;DR

This paper investigates how edge on-site potential differences influence the formation and tunability of edge states in a honeycomb topological magnon insulator, revealing mechanisms for controlling magnonic edge modes.

Contribution

It demonstrates the role of edge on-site potential differences in creating and tuning edge states, including Tamm-like and topologically protected states, in a honeycomb magnon insulator.

Findings

Edge on-site potential differences lead to edge state formation.

External potentials can tune edge state properties.

Topologically protected states coexist with Tamm-like states.

Abstract

The difference between the edge on-site potential and the bulk values in a magnonic topological honeycomb lattice leads to the formation of edge states in a bearded boundary, and the same difference is found to be the responsible for the absence of edge states in a zig-zag termination. In a finite lattice, the intrinsic on-site interactions along the boundary sites generate an effective defect and Tamm-like edge states appear for both zig-zag and bearded terminations. If a non-trivial gap is induced, Tamm-like and topologically protected edge states appear in the band structure. The effective defect can be strengthened by an external on-site potential and the dispersion relation, velocity and magnon-density of the edge states become tunable.