Imperfect electron-hole recollisions in high-harmonic generation in monolayer and bulk solids*

High-harmonic generation (HHG) in solids has attracted increased attention in recent years due to its exciting prospects for the engineering of new light sources and ultrafast spectroscopy methods. We present theoretical results on the process of imperfect recollisions in solid-state HHG, wherein an electron and a hole can recombine even when they are spatially separated. We consider two general types of materials: a monolayer material represented by hexagonal boron nitride (hBN) and a bulk solid represented by ZnO. In hBN, imperfect recollisions can be induced by linearly-polarized laser pulses, while elliptically-polarized pulses are required for ZnO. We discuss the general mechanisms and conditions for the imperfect recollisions.

References:
[L. Yue and M. B. Gaarde, Phys. Rev. Lett. 124, 153204 (2020)]
[L. Yue and M. B. Gaarde, Phys. Rev. A 101, 053411 (2020)]