# Strain tuned topology in the Haldane and the modified Haldane models

## TL;DR

This paper investigates how uniaxial strain affects the topological phases and edge modes in Haldane and modified Haldane models, revealing strain-induced phase transitions and tunable edge state properties.

## Contribution

It demonstrates that strain can induce topological phase transitions and control edge mode propagation in these models, providing insights for strain-engineered topological devices.

## Key findings

- Strain can switch topological phases with opposite Chern numbers.
- Edge mode dispersions are strain-dependent and can be reversed.
- Strain may destroy chiral and antichiral edge modes.

## Abstract

We study the interplay between a uniaxial strain and the topology of the Haldane and the modified Haldane models which, respectively, exhibit chiral and antichiral edge modes. The latter were, recently, predicted by Colom\'es and Franz (Phys. Rev. Lett. {\bf 120}, 086603 (2018)) and expected to take place in the transition metal dichalcogenides. Using the continuum approximation and a tight-binding approach, we investigate the effect of the strain on the topological phases and the corresponding edge modes. We show that the strain could induce transitions between topological phases with opposite Chern numbers or tune a topological phase into a trivial one. As a consequence, the dispersions of the chiral and antichiral edge modes are found to be strain dependent. The strain may reverse the direction of propagation of these modes and eventually destroy them. This effect may be used for strain-tunable edge currents in topological insulators and two-dimensional transition metal dichalcogenides.