IOQ-Kolloquium / Dr. Peter Jürgens-Goltermann (MBI Berlin)

The interaction of intense, ultrashort laser fields with solid targets drives the system far beyond the perturbative regime, giving rise to extreme nonlinear optical phenomena such as high-harmonic generation (HHG). Since the first demonstration of solid-state HHG, the field has rapidly evolved from source development toward a powerful spectroscopic tool for probing ultrafast dynamics in condensed matter.

In this presentation, I will discuss recent advances in using solid-state HHG and high-harmonic spectroscopy to investigate photoinduced electronic dynamics in solids. By combining few-cycle strong-field excitation with phase sensitive detection schemes, including high-harmonic interferometry, we access excitation-driven modifications of electronic structure on femtosecond timescales. These measurements enable us to track phenomena ranging from the generation of electron-hole pairs and transient bandgap renormalization to photoinduced insulator-metal transitions in correlated oxide materials.

Finally, I will present recent and ongoing efforts to extend high-harmonic spectroscopy toward the study of excitonic dynamics in solids, with a particular focus on excitonic dephasing and coherence times under strong-field and nonequilibrium conditions. Together, these results highlight the potential of solid state HHG as a sensitive probe of ultrafast electronic and collective dynamics in complex materials.