In the last decades, the developments in attosecond (attosecond =10-18second) physics enabled the real-time studies of electron dynamics in matter. Tracing the electron motion in its native time scale becomes crucial for the accurate clocking of microscopic phenomena. The attosecond physics field is based on the generation and exploiting the extreme-ultraviolet (XUV) attosecond pulses for probing the electron dynamics in atoms, molecule, and nanostructure (1, 2). Moreover, several other approaches have been developed to achieve the electron imaging resolution based on the HHG process, such as the self-electron diffraction to indirectly image the charge transfer in molecules (3). Alternatively, Ultrafast Electron Microscopy (UEM) and Diffraction (UED) tools have been developed to image the atomic motion in real-time and space. These electron imaging techniques have found a vast range of applications spans chemistry, physics, material science, and biology (4). Although, the technical challenges limit the temporal resolution of ultrafast electron imaging to the atomic motion time scale. Recently, we demonstrated the ability to control the electron pulses' temporal profile by optical gating using ultrashort laser pulses to enhance the temporal resolution in the ultrafast electron microscope (16-times) to 30 fs (5). The recent advancements in attosecond physics demonstrated the generation of attosecond laser pulses (6). We are adopting this pulse for generating subfemtosecond electron pulses by the attosecond optical gating to attain the attosecond temporal resolution in electron microscopy and diffraction imaging experiments, to establish what we socalled "Attomicroscopy" (7). This new electron imaging tools would permit mapping the electron dynamics in real-time and space. Such electron imaging will provide real-time access to electron dynamics in atoms and molecules and improve our understanding of chemistry and complicated quantum systems. In this talk, I will present the last progress in my lab for establishing the attosecond electron diffraction and microscopy with the ultimate goal of recording movies of electrons in action.
References
1. P. Corkum, F. Krausz, Attosecond science. Nature Physics 3, 381-387 (2007). 2. P. Agostini, L. F. DiMauro, The physics of attosecond light pulses. Reports on progress in physics 67, 813 (2004). 3. C. I. Blaga et al., Imaging ultrafast molecular dynamics with laser-induced electron diffraction. Nature 483, 194-197 (2012). 4. A. H. Zewail, Four-dimensional electron microscopy. Science 328, 187-193 (2010). 5. M. T. Hassan, J. S. Baskin, LiaoB, A. H. Zewail, High-temporal-resolution electron microscopy for imaging ultrafast electron dynamics. Nature Photonics 11, 425-430 (2017). 6. M. T. Hassan et al., Optical attosecond pulses and tracking the nonlinear response of bound electrons. Nature 530, 66-70 (2016). 7. M. T. Hassan, Attomicroscopy: from femtosecond to attosecond electron microscopy. Journal of Physics B: Atomic, Molecular and Optical Physics 51, 032005 (2018).
Join Zoom Meeting
https://osu.zoom.us/j/7030995726?pwd=ZzgxWHVpRjZtbHAwZG0wQnJpVnpFdz09
Password: 567548
