Speaker
Professor Alexandra Landsman
The Ohio State University
Abstract:
Recent advances in X鈥憆ay free鈥慹lectron laser (XFEL) technology have opened new opportunities to probe photoionization dynamics on attosecond timescales and to access strong鈥慺ield regimes at X鈥憆ay wavelengths that were previously experimentally inaccessible. In this talk, I will discuss two complementary classes of XFEL experiments that together illuminate the timing and mechanisms of electron emission in atoms and molecules. 听First, I will address听attosecond photoemission delays听measured using circular streaking techniques, with a focus on extending ionization鈥慸elay chronoscopy from听linearly to circularly polarized probes.听听I will also address the challenges of interpreting streaking delays at low photoelectron energies. 听Second, I will present recent theoretical work exploring a听new non鈥憄erturbative strong鈥慺ield X鈥憆ay regime, where multiphoton above鈥憈hreshold ionization (ATI) is driven by attosecond XFEL pulses. In helium, this regime produces distinct angular and spectral signatures that are clearly separated from perturbative harmonic contributions. 听Together, these studies demonstrate how XFELs enable both听quantitative attosecond chronoscopy听and听fundamental tests of strong鈥慺ield ionization physics听at short wavelengths, establishing a foundation for future experiments in atoms and molecules.
听Alexandra Landsman
Professor of Physics
The Ohio State University
Department of Physics
Physics Research Building
191 W Woodruff Ave, Columbus, OH 43210
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