Emerging topological bound states in Haldane model zigzag nanoribbons

This paper investigates zigzag nanoribbons based on the Haldane Chern insulator model, focusing on a reentrant topological phase characterized by the emergence of quasi zero-dimensional in-gap states. These bound states, localized at the ribbon ends, result from the hybridization of counter-propagating edge modes and exhibit robustness against on-site disorder. The Zak phase's behavior across the parameter space, showing π jumps during phase transitions, supports these findings. The effective mass inversion causing these jumps is explained using a low-energy framework. Non-uniform parameter setups also demonstrate topological bound states via the Jackiw-Rebbi mechanism. The observed properties are highly sensitive to the ribbon width.

Simone Traverso, Maura Sassetti, Niccolò Traverso Ziani