Large enhancement of nonlinear optical response of graphene nanoribbon heterojunctions with multiple topological interface states

TL;DR

This study demonstrates that increasing the number of topological interface states in graphene nanoribbon heterojunctions significantly enhances their nonlinear optical response and causes a red-shift in quantum plasmon frequency, revealing new nanoscale optical tuning methods.

Contribution

It introduces a quantum-mechanical approach to show how multiple topological states amplify nonlinear optical effects in graphene nanostructures.

Findings

Enhanced third-order nonlinear response with more topological states

Significant red-shift in quantum plasmon frequency due to topological states

Potential for nanoscale optical response tuning using topological interface states

Abstract

We investigate the nonlinear optical response of graphene nanoribbon (GNR) heterojunctions both without and with one or multiple topological interface states. By implementing a distant-neighbor quantum-mechanical (DNQM) method, we demonstrate a pronounced enhancement of the nonlinear optical response of GNR heterojunctions as the number of topological states at their interfaces increases. Specifically, we find that GNR heterojunctions with multiple topological interface states exhibit a notably stronger third-order nonlinear optical response in comparison with the similarly sized counterparts with a single topological interface state or without such states. Furthermore, we observe that the presence of topological interface states in GNR heterojunctions can induce a significant red-shift in their quantum plasmon frequency. Our results reveal the potential to enhance the nonlinear optical response at the nanoscale by increasing the number of topological interface states in graphene nanostructures or other topological systems.