Robustness of topologically sensitive harmonic generation in laser-driven linear chains

A many-order-of-magnitude difference in the harmonic yield from the two topological phases of finite, dimerizing linear chains in laser fields has recently been observed in all-electron time-dependent density-functional simulations [Bauer and Hansen, Phys. Rev. Lett. 120, 177401 (2018)]. In this work, we explore the robustness of the effect concerning the length of the chains, a continuous transition between the two topological phases, and disorder. A high robustness of both the degeneracy of the edge states in the topologically nontrivial phase as well as of the pronounced destructive interference, causing a dip in the harmonic spectra, in the topologically trivial phase is observed.