Tracking ultrafast solid-state dynamics using high harmonic spectroscopy

Understand

We establish time-resolved high harmonic generation (tr-HHG) as a powerful spectroscopy for photoinduced dynamics in strongly correlated materials through a detailed investigation of the insulator-to-metal transitions in vanadium dioxide.

• We benchmark our 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 in the equilibrium monoclinic phase over a wide range of excitation fluences.