Extreme Ultraviolet High-Harmonic Interferometry of Excitation-Induced Bandgap Dynamics in Solids

Lisa-Marie Koll; Simon Vendelbo Bylling Jensen; Pieter J. van Essen; Brian de Keijzer; Emilia Olsson; Jon Cottom; Tobias Witting; Anton Husakou; Marc J. J. Vrakking; Lars Bojer Madsen; Peter M. Kraus; Peter Jürgens

arXiv · 2502.20564

Extreme Ultraviolet High-Harmonic Interferometry of Excitation-Induced Bandgap Dynamics in Solids

Lisa-Marie Koll·Simon Vendelbo Bylling Jensen·Pieter J. van Essen·Brian de Keijzer·Emilia Olsson·Jon Cottom·Tobias Witting·Anton Husakou·Marc J. J. Vrakking·Lars Bojer Madsen·Peter M. Kraus·Peter Jürgens

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Abstract

Interferometry is a fundamental technique in physics, enabling precise measurements through the interference of waves. High-harmonic generation (HHG) in solids has emerged as a powerful method for probing ultrafast electronic dynamics within crystalline structures. In this study, we employed extreme ultraviolet (XUV) high-harmonic interferometry with phase-locked XUV pulse pairs to investigate excitation-induced bandgap dynamics in solids. Our experiments on amorphous SiO2 and crystalline MgO, complemented by analytical modeling and semiconductor Bloch equation simulations, reveal a correlation between transient bandgap modifications and variations in the phase of harmonic emission. These findings suggest a potential pathway for sub-cycle, all-optical control of band structure modifications, advancing prospects for petahertz-scale electronic applications and attosecond diagnostics of carrier dynamics.

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Lisa-Marie Koll, Simon Vendelbo Bylling Jensen, Pieter J. van Essen, Brian de Keijzer, Emilia Olsson, Jon Cottom, Tobias Witting, Anton Husakou, Marc J. J. Vrakking, Lars Bojer Madsen, Peter M. Kraus, Peter Jürgens. 2025-02-27. Extreme Ultraviolet High-Harmonic Interferometry of Excitation-Induced Bandgap Dynamics in Solids. https://arxiv.org/abs/2502.20564

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