2021/02/28 by Lun Yue, Mette B. Gaarde · 32 citations
Engineering · Physics and Astronomy · #Atomic physics #Band gap #Brillouin zone #Condensed matter physics #Electron #Electronic band structure #Elliptical polarization #Harmonics #High harmonic generation #Laser #Laser-Matter Interactions and Applications #Linear polarization #Physics #Quantum #Quantum mechanics #Quantum tunnelling #Semiclassical physics #Spectroscopy and Quantum Chemical Studies #Terahertz technology and applications #Wave packet #cond-mat.mes-hall #physics.atom-ph #physics.optics
paper · pdf · doi:10.1103/physreva.103.063105
published in Physical Review A 103(6) (American Physical Society) · 18 pages, 13 figures
openalex publication_date 2021/06/11 · arxiv created 2021/06/12 · arxiv updated 2021/06/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We theoretically investigate electron-hole recollisions in high-harmonic generation (HHG) in band-gap solids irradiated by linearly and elliptically polarized drivers. We find that in many cases, the emitted harmonics do not originate in electron-hole pairs created at the minimum band gap, where the tunneling probability is maximized, but rather in pairs created across an extended region of the Brillouin zone (BZ). In these situations, the analogy to gas-phase HHG in terms of the short- and long-trajectory categorizations is inadequate. Our analysis methodology comprises three complementary levels of theory: the numerical solutions to the semiconductor Bloch equations, an extended semiclassical recollision model, and a quantum wave-packet approach. We apply this methodology to two general material types with representative band structures: a bulk system and a hexagonal monolayer system. In the bulk, the interband harmonics generated using elliptically polarized drivers are found to originate not from tunneling at the minimum band gap \mathrm\ensuremathΓ, but from regions away from it. In the monolayer system driven by linearly polarized pulses, tunneling regions near different symmetry points in the BZ lead to distinct harmonic energies and emission profiles. We show that the imperfect recollisions, where an electron-hole pair recollide while being spatially separated, are important in both bulk and monolayer materials. The excellent agreement between our three levels of theory highlights and characterizes the complexity behind the HHG emission dynamics in solids, and expands on the notion of interband HHG as always originating in trajectories tunnelled at the minimum band gap. Our work furthers the fundamental understanding of HHG in periodic systems and will benefit the future design of experiments.