High-harmonic spectroscopy has been an interesting avenue to probe the structure and dynamics of isolated atoms and molecules. The spectroscopy is often based on the high-harmonic generation (HHG) mechanism, which was studied extensively in the early nineties. In fact, that understanding has been the basis of attosecond science and technology, which includes the generation of isolated attosecond pulse and imaging molecular orbitals. In 2010, the HHG process was also realized in condensed matter systems such as bulk crystals. Since then there have been interests in studying the solid-state HHG process, particularly to explore its potential as an ultrafast all-optical probe of materials, as well as its perspective as a compact attosecond light source[1,3]. Within a decade, solid-state HHG has immerged as one of the frontiers of attosecond science, along with a promising connection to a broader field of materials science. In this talk, I will give a brief overview of this connection and present our latest results in atomically thin two-dimensional crystals and three-dimensional topological insulators .
Selected Publications: 1. J. Lie et al, Perspective: Attosecond Science based on high harmonic generation from gases and solids, Nature Comm. 11, 2748 (2020) 2. S. Ghimire et al., Observation of high-order harmonics in a bulk crystal, Nature Physics 7, 2, 138 (2011) 3. S. Ghimire and D. Reis, Review: High-order harmonic generation from solids, Nature Physics Online November (2018). 4. D. Baykusheva et al., Strong-field physics in three-dimensional topological insulators, PRA 103, 023101 (2021)