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arXiv · 2607.16477

Measuring the dipole phase of Bloch-trajectory harmonics using a monolithic interferometer

Mohanad Awad·Julian Späthe·Paramjit C. Yadav·Mandakini Bhat·Zsolt Divéki·Eric Cormier·Bálint Kiss·Eszter Baradács·János Tomán·Zoltán Erdélyi·Thomas Siefke·Adrian N. Pfeiffer·Matthias Kübel
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Abstract

Uncovering the dipole phase of gas-phase high harmonic generation was instrumental to understanding the recollision physics underlying attosecond pulse generation. Corresponding measurements in the condensed phase have not yet yielded a consistent picture. Here, we present a compact and inherently stable approach to high-harmonic interferometry in thin-film solids. We employ it to reveal the dipole phase of high-harmonic generation in polycrystalline ZnO, driven by broadband mid-IR laser pulses. We demonstrate that, under the conditions of our experiments, recollisions facilitated by Bloch oscillations represent the dominant contribution to high-harmonic generation just above the bandgap.

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Mohanad Awad, Julian Späthe, Paramjit C. Yadav, Mandakini Bhat, Zsolt Divéki, Eric Cormier, Bálint Kiss, Eszter Baradács, János Tomán, Zoltán Erdélyi, Thomas Siefke, Adrian N. Pfeiffer, Matthias Kübel. 2026-07-17. Measuring the dipole phase of Bloch-trajectory harmonics using a monolithic interferometer. https://arxiv.org/abs/2607.16477

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