Near-bandgap harmonic generation in solids from multiple scattering revealed by complex quantum trajectories Huo, Xunqin Liu, Xiwang Yang, Shidong Song, Xiaohong Meier, Torsten Yang, Weifeng <jats:p> High-harmonic generation in solids enables probing of strong-field electron dynamics in condensed matter and the development of compact ultrafast light sources. Whereas most studies have focused on above-bandgap high-order harmonics, which are usually interpreted through short electron-hole trajectories that recombine within one optical cycle, the microscopic origin of low-order emission near the bandgap remains poorly understood. Here, we investigate near-bandgap harmonic generation in ZnO by combining semiconductor Bloch equations with a complex-time quantum-trajectory analysis. Our results indicate that these harmonics are not a continuation of the short trajectory. Rather, they originate from multiple-scattering trajectories, in which the electron-hole pair undergoes repeated Bragg scattering at the Brillouin-zone boundary and electron-hole reencounter near the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:mi mathvariant="normal">Γ</a:mi> </a:math> point before the actual recombination occurs. We identify that the imaginary part of the electron-hole displacement provides a practical diagnostic of the residual tunneling memory. Real-space electron-hole overlap alone does not imply coherent recombination unless the full complex displacement vanishes. These results clarify the microscopic picture of near-bandgap harmonic emission in ZnO and offer a framework for interpreting phase-resolved strong-field dynamics in solids. </jats:p> American Physical Society (APS) 2026 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_6501 https://ris.uni-paderborn.de/record/67146 Huo X, Liu X, Yang S, Song X, Meier T, Yang W. Near-bandgap harmonic generation in solids from multiple scattering revealed by complex quantum trajectories. <i>Physical Review Research</i>. 2026;8(3). doi:<a href="https://doi.org/10.1103/l939-jglf">10.1103/l939-jglf</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1103/l939-jglf info:eu-repo/semantics/altIdentifier/issn/2643-1564 info:eu-repo/semantics/closedAccess