Enhanced high-order harmonic generation by spatially-structured-light–induced topological-edge-state dynamics

We theoretically investigate the topological edge-state impact on high-order harmonic generation (HHG) in solids, with a focus on the modification of the topological edge-state dynamics by spatially structured (SS) light. Our findings reveal an underlying mechanism coupling the spatial inhomogeneity of light with the topological states, which leads to a notable but counterintuitive enhancement of HHG yields by SS light, even with a lower average field-intensity compared to the conventional spatially homogeneous light. We attribute this giant coupling effect to the dynamical modulation of the energy bands by the SS light in the HHG process, building an ``electron lift'' scenario of the topological edge states. Our study not only highlights the intricate interplay between spatial inhomogeneity of laser fields and topological condensed matter but also paves pathways for manipulating electron dynamics in solids using the unique properties of SS light.