Formation of the solid-state high-order harmonic generation plateau through destructive interference

In frequently studied two-band models for solid-state high-harmonic generation, interband harmonics in principle can range from the minimum to maximum bandgap. However, it is known that a laser-intensity dependent cutoff exists may be well below bandgap unless laser intensity so high electrons explore entire Brillouin zone. We show this formed by destructive interference of emission starting at different initial states The calculations work are Su-Schrieffer-Heeger chains but our findings apply other systems as well. Only when sampling zone fine enough or, equivalently, finite chain long position space, complete and forms cutoff. For coarser shorter all between emitted. A time-frequency analysis shows how certain trajectories responsible formation