Effect of Physical Barriers on High-Harmonic Generation in Liquid-Phase
Abstract
High-harmonic generation (HHG) in liquid-phase systems presents fundamental differences from gas and solid phases, notably a reduction in the harmonic cutoff, its apparent independence from laser parameters, and the appearance of a second plateau. In this work, we introduce a one-dimensional quantum model that incorporates physical boundaries to simulate the effect of solvation shells in liquid water by means of a complex absorbing potential (CAP). By systematically varying the position, width, and strength of the CAP, we explore how these physical constraints influence the HHG spectrum. Our findings confirm that spatial confinement, specifically the physical truncation of electron trajectories, is the primary factor governing the cutoff in liquid-phase HHG. This confinement leads to a cutoff that is independent of laser intensity and wavelength, aligning with experimental observations and existing hypotheses proposed by Mondal et al. in 2023 and 2026. Furthermore, by implementing a semi-transparent CAP, we successfully reproduce the less intense second plateau observed in liquid-phase HHG. Time-frequency analysis confirms that this characteristic spectral feature is driven by partial wave-packet transmission through the solvation shells, which allows a surviving fraction of electrons to undergo longer continuum excursions. Our one-dimensional approach successfully isolates the fundamental role of physical boundaries in liquid-phase HHG, providing a clear and intuitive understanding of the underlying physics.
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BibTeX
@misc{darna2026effect,
title = {{Effect of Physical Barriers on High-Harmonic Generation in Liquid-Phase}},
author = {Beatriz Darna and Marie Labeye},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.26045},
eprint = {2610.26045},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.26045},
note = {CC BY-NC-SA 4.0},
}
RIS
TY - UNPB
TI - Effect of Physical Barriers on High-Harmonic Generation in Liquid-Phase
AU - Beatriz Darna
AU - Marie Labeye
PY - 2026
DA - 2026/10/19
PB - arXiv
DO - 10.48550/arxiv.2610.26045
UR - https://arxiv.org/abs/2610.26045
AB - High-harmonic generation (HHG) in liquid-phase systems presents fundamental differences from gas and solid phases, notably a reduction in the harmonic cutoff, its apparent independence from laser parameters, and the appearance of a second plateau. In this work, we introduce a one-dimensional quantum model that incorporates physical boundaries to simulate the effect of solvation shells in liquid water by means of a complex absorbing potential (CAP). By systematically varying the position, width, and strength of the CAP, we explore how these physical constraints influence the HHG spectrum. Our findings confirm that spatial confinement, specifically the physical truncation of electron trajectories, is the primary factor governing the cutoff in liquid-phase HHG. This confinement leads to a cutoff that is independent of laser intensity and wavelength, aligning with experimental observations and existing hypotheses proposed by Mondal et al. in 2023 and 2026. Furthermore, by implementing a semi-transparent CAP, we successfully reproduce the less intense second plateau observed in liquid-phase HHG. Time-frequency analysis confirms that this characteristic spectral feature is driven by partial wave-packet transmission through the solvation shells, which allows a surviving fraction of electrons to undergo longer continuum excursions. Our one-dimensional approach successfully isolates the fundamental role of physical boundaries in liquid-phase HHG, providing a clear and intuitive understanding of the underlying physics.
ER -