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arXiv · 2508.14212

A unified perspective of high-harmonic generation in gases and solids

Adam Thorpe·Neda Boroumand·Graeme Bart·Lu Wang·Giulio Vampa·Thomas Brabec
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Abstract

We present a quantum optical generalization of the quantum-matter Lewenstein model of high-harmonic generation (HHG) in gases that contains two channels corresponding to the inter- and intraband HHG in solids. Both channels can be presented as a semiclassical current multiplied by the vacuum field strength, resulting in a quantitative correction and a faster roll-off of the harmonic power with order than in previous theories. In gases, like in solids, intraband HHG dominates at low orders; the switchover harmonic corresponds to a specific photon energy, independent of pump wavelength.

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Adam Thorpe, Neda Boroumand, Graeme Bart, Lu Wang, Giulio Vampa, Thomas Brabec. 2025-08-19. A unified perspective of high-harmonic generation in gases and solids. https://arxiv.org/abs/2508.14212

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