Strain-induced topological phase transition in graphene nanoribbons

The electronic properties of two-dimensional (2D) nanostructures are highly responsive to changes in their geometry, making strain-engineering a powerful method for tuning the electronic characteristics of flexible 2D nanostructures. Quasi-one-dimensional (1D) graphene nanoribbons (GNRs) are crucial quantum building blocks in the development of next-generation flexible devices and have recently been recognized for possessing distinct symmetry-protected topological phases characterized by a ${Z}_{2}$ invariant. In this study, utilizing the tight-binding (TB) model, we present compelling evidence that the topological phase transition in 1D GNRs can be effectively controlled through strain-engineering. Furthermore, we investigate the behavior of heterojunctions composed of different types of AGNR segments and reveal that strain can create or eliminate the junction state while significantly enhancing the end states. Our study presents a new method for tuning topological phase transitions in flexible quasi-1D materials, offering an efficient way to control over junction state and end states.