Tracking ultrafast solid-state dynamics using high harmonic spectroscopy

• Published in: Physical review research Vol. 3; no. 2; p. 023250
• Main Authors: Bionta, Mina R., Haddad, Elissa, Leblanc, Adrien, Gruson, Vincent, Lassonde, Philippe, Ibrahim, Heide, Chaillou, Jérémie, Émond, Nicolas, Otto, Martin R., Jiménez-Galán, Álvaro, Silva, Rui E. F., Ivanov, Misha, Siwick, Bradley J., Chaker, Mohamed, Légaré, François
• Format: Journal Article
• Language: English
• Published: American Physical Society 28.06.2021
• Subjects: Optics; Physics
• ISSN: 2643-1564; 2643-1564
• DOI: 10.1103/PhysRevResearch.3.023250

We establish time-resolved high harmonic generation (tr-HHG) as a powerful spectroscopy method for tracking photoinduced dynamics in strongly correlated materials through a detailed investigation of the insulatorto-metal phase transitions in vanadium dioxide. We benchmark the technique by comparing our measurements to established momentum-resolved ultrafast electron diffraction, and theoretical density functional calculations. Tr-HHG allows distinguishing of individual dynamic channels, including a transition to a thermodynamically hidden phase. In addition, the HHG yield is shown to be modulated at a frequency characteristic of a coherent phonon of the equilibrium monoclinic phase over a wide range of excitation fluences. These results demonstrate that tr-HHG is capable of tracking complex dynamics in solids through its sensitivity to the band structure.