Attosecond Science: Probing electron dynamics in complex systems

The emergence of attosecond spectroscopy has offered researchers a new experimental tool, which provides unprecedented temporal resolution for the direct measurement and control of electronic processes. Pioneering studies have obtained unique physical insights by taking snapshots of atomic and molecular phenomena on the natural timescale of electrons. Ongoing efforts aim to expand the scope of attosecond XUV research for exploration of complex dynamics in molecules and materials. My lab has conducted frontline investigations to probe the electronic complexity stemming from coupled nuclear motion, electronic correlations, external fields, or a combination thereof. I will present our latest results on the coherent evolution of electron hole near a conical intersection of a polyatomic molecule. Such conical intersections induce nuclear-motion-mediated electron dynamics and serve as nature’s energy funnels in many biochemical processes (e.g. DNA repair, light harvesting etc.). In a similar context, we have investigated electron-phonon coupling and electronic correlations in carbon nanomaterials. I will show that apart from the sensitive measurements of electronic couplings, we can also monitor the evolution of quantum coherence in charge transfer processes. Finally, I will discuss our ongoing work on the generation of ‘isolated’ attosecond pulses and their application in study of correlation-driven charge migration in molecules and magnetic materials. Such interdisciplinary efforts will open the attosecond field for a broad set of applications in physics, chemistry and material sciences.