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arXiv · 2605.21223

High-order harmonic generation from an atom in a disordered environment

Simon His·Camille Lévêque·Jérémie Caillat·Richard Taïeb·Jonathan Dubois
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Abstract

Using one-dimensional simulations analyzed through the lens of open quantum systems, we study the photoelectron's strong-field dynamics from an atom surrounded by a scattering environment stochastically structured. We theoretically investigate high-order harmonic generation from this situation. We show that local dephasing of the photoelectron wavepacket induced by elastic scattering leads to global decoherence. This drives a transition from quantum to classical behavior, as witnessed by the photoelectron probability density localizing around specific trajectories of the classical analog system: unstable periodic orbits. This phenomenon mirrors quantum scars traditionally observed in the eigenfunctions of time-independent systems, such as quantum billiards. Here, it emerges in-situ within a time-dependent framework, manifesting directly in the real-time dynamics from the ground state rather than solely through spectral analysis.

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Simon His, Camille Lévêque, Jérémie Caillat, Richard Taïeb, Jonathan Dubois. 2026-05-20. High-order harmonic generation from an atom in a disordered environment. https://arxiv.org/abs/2605.21223

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