Ultrafast Dynamics of Laser-Excited Topological Edge States in Graphene Nanoribbon Heterostructures

The electromagnetic properties of finite graphene nanoribbon (GNR) heterostructures are strongly affected by localized topological edge states [1]. Recently, we showed for 7-9-armchair-GNRs that the increased electronic correlations of these states results in increased magnetic moments at the ribbon edges accompanied by a significant energy renormalization of the topological end states, even in the presence of a metallic substrate [2]. Here, we improve the description of the system by including long-range Coulomb interactions within the Pariser–Parr–Pople Model. Employing our newly developed DSL* approximation within the G1–G2 scheme [3-5] we study the ultrafast electron response in a freestanding unit cell of the 7-9-armchair-GNR following a laser excitation. We find that the excited localized edge states play a major role in the subsequent electron dynamics.

[1] J.-P. Joost et al., Nano Letters 19, 9045 (2019)

[2] D. J. Rizzo et al., Nature 560, 204 (2018)

[3] N. Schlünzen et al., Phys. Rev. Lett. 124, 076601 (2020)

[4] J.-P. Joost et al., Phys. Rev. B 101, 245101 (2020)

[5] J.-P. Joost et al., Phys. Rev. B 105, 165155 (2022)