Edge-state-induced correlation effects in two-color high-harmonic generation

We show that two-color high-harmonic spectroscopy can reveal finite-size and edge-state-induced dynamic electron correlation effects in a generic nanostructured band-gap material. Compared to the response of a bulk sample, we demonstrate a significant correlation-induced increase in the efficiency of the generated signal over a wide range of frequencies by harnessing the power of these ultrafast many-electron dynamics.